Metabolism: Wikis

  
  

Encyclopedia

From Wikipedia, the free encyclopedia

Structure of the coenzyme adenosine triphosphate, a central intermediate in energy metabolism
.Metabolism is the set of chemical reactions that happen in living organisms to maintain life.^ Metabolism is the complete set of chemical reactions that occur in living cells .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Although living organisms' amazing complexity appears to contradict this law, life is possible as all organisms are open system s that exchange matter and energy with their surroundings.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Many proteins are the enzymes that catalyze the chemical reactions in metabolism.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments.^ These processes are the basis of life , allowing cells to grow and reproduce, maintain their structures, and respond to their environments.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Metabolic regulation also allows organisms to respond to signals and interact actively with their environments.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Stevia's structure does not allow it to brown or carmelize like sucrose, so it is not recommended for cooking items that require these outcomes.

.Metabolism is usually divided into two categories.^ More: Metabolism is usually divided into two categories: .
  • Glossary: Metabolism 28 January 2010 0:27 UTC www.greenfacts.org [Source type: Reference]

^ These reactions are divided into two categories.
  • Metabolism 28 January 2010 0:27 UTC bioweb.wku.edu [Source type: FILTERED WITH BAYES]

^ Metabolism is split into two categories.

Catabolism breaks down organic matter, for example to harvest energy in cellular respiration. .Anabolism, uses energy to construct components of cells such as proteins and nucleic acids.^ Anabolism , on the other hand, uses this energy to construct components of cells such as proteins and nucleic acids .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The amino acids or sugars released by these extracellular enzymes are then pumped into cells by specific active transport proteins.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Firstly, the production of precursors such as amino acids , monosaccharides , isoprenoids and nucleotides , secondly, their activation into reactive forms using energy from ATP, and thirdly, the assembly of these precursors into complex molecules such as proteins , polysaccharides , lipids and nucleic acids .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.The chemical reactions of metabolism are organized into metabolic pathways, in which one chemical is transformed through a series of steps into another chemical, by a sequence of enzymes.^ Many proteins are the enzymes that catalyze the chemical reactions in metabolism.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In biochemistry, a metabolic pathway is a series of chemical reactions occurring within a cell.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In each pathway a principal chemical is modified by chemical reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Enzymes are crucial to metabolism because they allow organisms to drive desirable reactions that require energy and will not occur by themselves, by coupling them to spontaneous reactions that release energy.^ Enzymes are crucial to metabolism because they allow cells to drive desirable but thermodynamically unfavorable reactions by coupling them to favorable ones.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These reactions require energy.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Organisms can be further classified by ultimate source of their energy: photoautotrophs and photoheterotrophs obtain energy from light, whereas chemoautotrophs and chemoheterotrophs obtain energy from inorganic oxidation reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.As enzymes act as catalysts they allow these reactions to proceed quickly and efficiently.^ These three families differ in terms of their tissue distribution, reaction kinetics, efficiency of substrate utilization, and sensitivity to inhibitors.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

.Enzymes also allow the regulation of metabolic pathways in response to changes in the cell's environment or signals from other cells.^ Extrinsic control involves a cell in a multicellular organism changing its metabolism in response to signals from other cells.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Metabolic regulation also allows organisms to respond to signals and interact actively with their environments.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Enzymes also allow the regulation of metabolic pathways in response to changes in the cell's environment or signals from other cells.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.The metabolism of an organism determines which substances it will find nutritious and which it will find poisonous.^ The metabolism of an organism determines which substances it will find nutritious and which it will find poisonous .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.For example, some prokaryotes use hydrogen sulfide as a nutrient, yet this gas is poisonous to animals.^ For example, some prokaryotes use hydrogen sulfide as a nutrient, yet this gas is poisonous to animals.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Hydrogen sulfide (hydrogen sulphide in British English) is the chemical compound with the formula H 2 S. This colorless, toxic and flammable gas is responsible for the foul odor of rotten eggs and flatulence.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[1] .The speed of metabolism, the metabolic rate, also influences how much food an organism will require.^ If you are limiting your portion sizes of these foods, your body will slow your metabolic rate and you will tire easily.

^ Additional studies will be required to determine how FGF21 stimulates lipolysis and the relationship between its effects on glucose and fatty acid metabolism.
  • Cell Metabolism -- Inagaki et al. 11 September 2009 19:58 UTC saturn.med.nyu.edu [Source type: Academic]

.A striking feature of metabolism is the similarity of the basic metabolic pathways between even vastly different species.^ A striking feature of metabolism is the similarity of the basic metabolic pathways between even vastly different species.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In animals, glucuronidation is a major thyroid hormone metabolism pathway; however, there are species- 33 and gender-dependent 40 variations in glucuronidation enzyme activity and specificity for thyroid hormones.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

^ Another possibility is that some parts of metabolism might exist as "modules" that can be reused in different pathways and perform similar functions on different molecules.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.For example, the set of carboxylic acids that are best known as the intermediates in the citric acid cycle are present in all organisms, being found in species as diverse as the unicellular bacteria Escherichia coli and huge multicellular organisms like elephants.^ For example, the set of chemical intermediates in the citric acid cycle are found universally, among living cells as diverse as the unicellular bacteria Escherichia coli and huge multicellular organisms like elephants .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The glycerol enters glycolysis and the fatty acids are broken down by beta oxidation to release acetyl-CoA, which then is fed into the citric acid cycle.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ He discovered the urea cycle and later, working with Hans Kornberg , the citric acid cycle and the glyoxylate cycle.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[2] .These striking similarities in metabolism are probably due to the high efficiency of these pathways, and their early appearance in evolutionary history.^ This shared metabolic structure is most likely the result of the high efficiency of these pathways, and of their early appearance in evolutionary history.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ "Evolutionary optimization of metabolic pathways.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Currently, no data is available to determine a role of nutritional status and lifestyle factors for these enzyme pathways with respect to the metabolic fate of thyroid hormones.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

[3][4]

Contents

Key biochemicals

Structure of a triacylglycerol lipid
.Most of the structures that make up animals, plants and microbes are made from three basic classes of molecule: amino acids, carbohydrates and lipids (often called fats).^ Most of the structures that make up animals, plants and microbes are made from three basic classes of molecule: amino acids , carbohydrates and lipids (often called fats ).
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Carbohydrates are the most abundant biological molecules, and fill numerous roles, such as the storage and transport of energy ( starch , glycogen ) and structural components ( cellulose in plants, chitin in animals).
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Fatty acids release more energy upon oxidation than carbohydrates because carbohydrates contain more oxygen in their structures.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.As these molecules are vital for life, metabolic reactions focus on making these molecules during the construction of cells and tissues, or breaking them down and using them as a source of energy, in the digestion and use of food.^ These include breaking down and oxidising food molecules as well as reactions that trap the energy in sunlight.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ As these molecules are vital for life, metabolism focuses on making these molecules, in the construction of cells and tissues, or breaking them down and using them as a source of energy, in the digestion and use of food.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These reactions require energy.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Many important biochemicals can be joined together to make polymers such as DNA and proteins.^ There is no cap on many carb- containing foods such as most vegetables, nuts, nut butters, cheeses, proteins.

^ The techniques that are used to join together genes from different sources in a test tube and to insert foreign DNA into an organism's genome are collectively called __________.
  • Biology 100 Practice Challenge Exam I-2007 11 September 2009 8:27 UTC academics.tctc.edu [Source type: Academic]

.These macromolecules are essential parts of all living organisms.^ These macromolecules are essential parts of all living organisms.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Although living organisms' amazing complexity appears to contradict this law, life is possible as all organisms are open system s that exchange matter and energy with their surroundings.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Some of the most common biological polymers are listed in the table below.^ Some of the most common biological polymers are listed in the table below.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Table 4 lists some of the more common inborn errors of metabolism, classified by type of metabolic disorder.
  • Inborn Errors of Metabolism in Infancy and Early Childhood: An Update - June 1, 2006 - American Family Physician 28 January 2010 0:27 UTC www.aafp.org [Source type: Academic]

Type of molecule Name of monomer forms Name of polymer forms Examples of polymer forms
Amino acids Amino acids Proteins (also called polypeptides) Fibrous proteins and globular proteins
Carbohydrates Monosaccharides Polysaccharides Starch, glycogen and cellulose
Nucleic acids Nucleotides Polynucleotides DNA and RNA

Amino acids and proteins

.Proteins are made of amino acids arranged in a linear chain and joined together by peptide bonds.^ Amino acids and proteins .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Proteins are large organic compounds made of amino acids arranged in a linear chain and joined together by peptide bonds between the carboxyl and amino groups of adjacent amino acid residues.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Proteins are made of amino acids arranged in a linear chain and joined together by peptide bonds .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Many proteins are the enzymes that catalyze the chemical reactions in metabolism.^ Thyroid hormones can be metabolized in peripheral tissue by deiodination, conjugation, deamination, and decarboxylation enzyme reactions.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

^ Iodine then binds to the number 3 position in the tyrosyl ring in a reaction catalyzed by thyroid peroxidase enzyme, a reaction yielding 3-monoiodotyrosine (MIT).
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

^ Conclusion Thyroid hormones are metabolized in peripheral tissues by conjugation, deamination, decarboxylation, and a cascade of monodeiodination enzyme reactions.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

.Other proteins have structural or mechanical functions, such as the proteins that form the cytoskeleton, a system of scaffolding that maintains the cell shape.^ Other proteins have structural or mechanical functions, such as the proteins in the cytoskeleton that form a system of scaffolding to maintain cell shape.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Overall, these studies give a good view of the structure and function of simple metabolic pathways, but are inadequate when applied to more complex systems such as the metabolism of a complete cell.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These processes are the basis of life , allowing cells to grow and reproduce, maintain their structures, and respond to their environments.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[5] .Proteins are also important in cell signaling, immune responses, cell adhesion, active transport across membranes, and the cell cycle.^ The protein is predicted to be a lysosomal membrane transporter, however, the exact ligand remains to be identified [ Rutsch et al 2009 ].
  • Disorders of Intracellular Cobalamin Metabolism -- GeneReviews -- NCBI Bookshelf 28 January 2010 0:27 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

[6]

Lipids

.Lipids are the most diverse group of biochemicals.^ Lipids are the most diverse group of biochemicals.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Their main structural uses are as part of biological membranes such as the cell membrane, or as a source of energy.^ Their main structural uses are as part of biological membranes such as the cell membrane , or as a source of energy.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The electrons then flow to the cytochrome b6f complex , which uses their energy to pump protons across the thylakoid membrane in the chloroplast .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ As these molecules are vital for life, metabolism focuses on making these molecules, in the construction of cells and tissues, or breaking them down and using them as a source of energy, in the digestion and use of food.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[6] .Lipids are usually defined as hydrophobic or amphipathic biological molecules that will dissolve in organic solvents such as benzene or chloroform.^ Lipids are usually defined as hydrophobic or amphipathic biological molecules that will dissolve in organic solvents such as benzene or chloroform .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Lipids can be broadly defined as any fat-soluble (hydrophobic), naturally-occurring molecules.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In the first, large organic molecules such as proteins , polysaccharides or lipids are digested into their smaller components outside cells.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[7] .The fats are a large group of compounds that contain fatty acids and glycerol; a glycerol molecule attached to three fatty acid esters is a triacylglyceride.^ However on day 5, the rate of fatty acid oxidation was significantly higher in the SW-selected line relative to the LW(f) line of the same block for each of the three blocks.
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

^ In addition, ethyl glucuronide (EtG) in urine, and fatty acid ethyl esters (FAEEs) and EtG in hair were determined using LC-MS/MS and gas chromatograph/mass spectrometer.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

^ Boxes next to triglyceride and phospholipid indicate that these compounds are produced from phosphatidate by removal of the phosphate group (to produce diglyceride) and subsequent addition of (1) a third fatty acid (triglyceride), or (2) a phosphorylated compound such as phosphocholine (phospholipid).
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

[8] .Several variations on this basic structure exist, including alternate backbones such as sphingosine in the sphingolipids, and hydrophilic groups such as phosphate in phospholipids.^ There are several types of ADH and ALDH, each of which may exist in several variants (i.e., isoforms) that differ in their ability to break down alcohol and its toxic metabolite acetaldehyde.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

.Steroids such as cholesterol are another major class of lipids that are made in cells.^ Steroids such as cholesterol are another major class of lipids that are made in cells.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Lanosterol can then be converted into other steroids such as cholesterol and ergosterol .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In the first, large organic molecules such as proteins , polysaccharides or lipids are digested into their smaller components outside cells.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[9]

Carbohydrates

The straight chain form consists of four C H O H groups linked in a row, capped at the ends by an aldehyde group C O H and a methanol group C H 2 O H. To form the ring, the aldehyde group combines with the O H group of the next-to-last carbon at the other end, just before the methanol group.
Glucose can exist in both a straight-chain and ring form.
.Carbohydrates are straight-chain aldehydes or ketones with many hydroxyl groups that can exist as straight chains or rings.^ Carbohydrates are straight-chain aldehydes or ketones with many hydroxyl groups that can exist as straight chains or rings.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Glucose can exist in both a straight-chain and ring form.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ As any of the hydroxyl groups on the ring of the substrate can be acceptors, the polysaccharides produced can have straight or branched structures.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Carbohydrates are the most abundant biological molecules, and fill numerous roles, such as the storage and transport of energy (starch, glycogen) and structural components (cellulose in plants, chitin in animals).^ Starch , glycogen and cellulose .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Carbohydrates are the most abundant biological molecules, and fill numerous roles, such as the storage and transport of energy ( starch , glycogen ) and structural components ( cellulose in plants, chitin in animals).
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Triglyceride is the most abundant energy storage molecule, while phospholipid, the second most abundant lipid class, is the primary component of biological membranes.
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

[6] The basic carbohydrate units are called monosaccharides and include galactose, fructose, and most importantly glucose. .Monosaccharides can be linked together to form polysaccharides in almost limitless ways.^ Monosaccharides can be linked together to form polysaccharides in almost limitless ways.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Just as the letters of the alphabet can be combined to form an almost endless variety of words, amino acids can be linked in varying sequences to form a huge variety of proteins.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[10]

Nucleotides

.The polymers DNA and RNA are long chains of nucleotides.^ The polymers DNA and RNA are long chains of nucleotides .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.These molecules are critical for the storage and use of genetic information, through the processes of transcription and protein biosynthesis.^ Essentially no information has been available on variation in in vivo processes such as rates of lipid biosynthesis or oxidation that underlie life history adaptations and trade-offs.
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

[6] .This information is protected by DNA repair mechanisms and propagated through DNA replication.^ This information is protected by DNA repair mechanisms and propagated through DNA replication .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ It is hypothesized that the mechanism through which these alleles protect against alcohol dependence is by causing elevations in acetaldehyde, which in turn cause an increased response to alcohol.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

.A few viruses have an RNA genome, for example HIV, which uses reverse transcription to create a DNA template from its viral RNA genome.^ The FGF21 promoter constructs −1497/+5, −977/+5, and −98/+5 were generated by PCR using 129Sv mouse genomic DNA and the following oligonucleotides: −1497 forward, 5′-GACGGCAAGCTTGGCCTGAAGCCTCACCTTGAC-3′; −977 forward, 5′-CCCAAGCTTCCAAAGCACCTTGTAGCTTAA-3′; −98 forward, 5′-GACGGCAAGCTTGGTTCCTGCCAAGTGTGTC-3′; +5 reverse, 5′-GACGGCCTCGAGTGTCTGGTGAACGCAGAAATACCC-3′.
  • Cell Metabolism -- Inagaki et al. 11 September 2009 19:58 UTC saturn.med.nyu.edu [Source type: Academic]

[11] .RNA in ribozymes such as spliceosomes and ribosomes is similar to enzymes as it can catalyze chemical reactions.^ Many proteins are the enzymes that catalyze the chemical reactions in metabolism.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ RNA in ribozymes such as spliceosomes and ribosomes is similar to enzymes as it can catalyze chemical reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Enzyme activity can be modulated by numerous foreign compounds, such as common chemicals and drugs.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

Individual nucleosides are made by attaching a nucleobase to a ribose sugar. .These bases are heterocyclic rings containing nitrogen, classified as purines or pyrimidines.^ These bases are heterocyclic rings containing nitrogen, classified as purines or pyrimidines .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Nucleotides also act as coenzymes in metabolic group transfer reactions.^ Nucleotides also act as coenzymes in metabolic group transfer reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Each class of group-transfer reaction is carried out by a particular coenzyme, which is the substrate for a set of enzymes that produce it, and a set of enzymes that consume it.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ This nucleotide is used to transfer chemical energy between different chemical reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[12]

Coenzymes

Structure of the coenzyme acetyl-CoA.The transferable acetyl group is bonded to the sulfur atom at the extreme left.
.Metabolism involves a vast array of chemical reactions, but most fall under a few basic types of reactions that involve the transfer of functional groups.^ Metabolism involves a vast array of chemical reactions, but most fall under a few basic types of reactions that involve the transfer of functional groups .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Nucleotides also act as coenzymes in metabolic group transfer reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Many proteins are the enzymes that catalyze the chemical reactions in metabolism.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[13] .This common chemistry allows cells to use a small set of metabolic intermediates to carry chemical groups between different reactions.^ This nucleotide is used to transfer chemical energy between different chemical reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Metabolism is the complete set of chemical reactions that occur in living cells .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ This common chemistry allows cells to use a small set of metabolic intermediates to carry chemical groups between different reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[12] These group-transfer intermediates are called coenzymes. .Each class of group-transfer reaction is carried out by a particular coenzyme, which is the substrate for a set of enzymes that produce it, and a set of enzymes that consume it.^ Each class of group-transfer reaction is carried out by a particular coenzyme, which is the substrate for a set of enzymes that produce it, and a set of enzymes that consume it.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ "Mechanisms of enzyme-catalyzed group transfer reactions".
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Nucleotides also act as coenzymes in metabolic group transfer reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.These coenzymes are therefore continuously being made, consumed and then recycled.^ These coenzymes are therefore continuously being made, consumed and then recycled.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[14]
.One central coenzyme is adenosine triphosphate (ATP), the universal energy currency of cells.^ ATP can be used as the cell's energy currency because ________.
  • Biology 100 Practice Challenge Exam I-2007 11 September 2009 8:27 UTC academics.tctc.edu [Source type: Academic]

^ The most central coenzyme is adenosine triphosphate (ATP), the universal energy currency of cells.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Next, these smaller molecules are taken up by cells and converted to yet smaller molecules, usually acetyl coenzyme A (CoA), which releases some energy.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

This nucleotide is used to transfer chemical energy between different chemical reactions. .There is only a small amount of ATP in cells, but as it is continuously regenerated, the human body can use about its own weight in ATP per day.^ There is only a small amount of ATP in cells, but as it is continuously regenerated, the human body can use about its own weight in ATP per day.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ While administration of 0.2 g/kg body weight for 15 days produced no significant change in serum T4 levels, serum T3 concentrations were increased.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

^ In human nutrition , most vitamins function as coenzymes after modification; for example, all water-soluble vitamins are phosphorylated or are coupled to nucleotides when they are used in cells.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[14] .ATP acts as a bridge between catabolism and anabolism, with catabolic reactions generating ATP and anabolic reactions consuming it.^ ATP acts as a bridge between catabolism and anabolism, with catabolic reactions generating ATP and anabolic reactions consuming it.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Nicotinamide adenine dinucleotide exists in two related forms in the cell, NADH and NADPH. The NAD + /NADH form is more important in catabolic reactions, while NADP + /NADPH is used in anabolic reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The purpose of these catabolic reactions is to provide the energy and components needed by anabolic reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.It also serves as a carrier of phosphate groups in phosphorylation reactions.^ It also serves as a carrier of phosphate groups in phosphorylation reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Each class of group-transfer reaction is carried out by a particular coenzyme, which is the substrate for a set of enzymes that produce it, and a set of enzymes that consume it.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ This common chemistry allows cells to use a small set of metabolic intermediates to carry chemical groups between different reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

A vitamin is an organic compound needed in small quantities that cannot be made in the cells. .In human nutrition, most vitamins function as coenzymes after modification; for example, all water-soluble vitamins are phosphorylated or are coupled to nucleotides when they are used in cells.^ In human nutrition , most vitamins function as coenzymes after modification; for example, all water-soluble vitamins are phosphorylated or are coupled to nucleotides when they are used in cells.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The modified water-soluble xenobiotic can then be pumped out of cells and in multicellular organisms may be further metabolized before being excreted (phase III).
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Enzymes are crucial to metabolism because they allow cells to drive desirable but thermodynamically unfavorable reactions by coupling them to favorable ones.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[15] .Nicotinamide adenine dinucleotide (NADH), a derivative of vitamin B3 (niacin), is an important coenzyme that acts as a hydrogen acceptor.^ Nicotinamide adenine dinucleotide (NADH), a derivative of vitamin B 3 ( niacin ), is an important coenzyme that acts as a hydrogen acceptor.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Finally, the acetyl group on the CoA is oxidised to water and carbon dioxide in the citric acid cycle and electron transport chain , releasing the energy that is stored by reducing the coenzyme nicotinamide adenine dinucleotide (NAD + ) into NADH. Digestion .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Nicotinamide adenine dinucleotide exists in two related forms in the cell, NADH and NADPH. The NAD + /NADH form is more important in catabolic reactions, while NADP + /NADPH is used in anabolic reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Hundreds of separate types of dehydrogenases remove electrons from their substrates and reduce NAD+ into NADH. This reduced form of the coenzyme is then a substrate for any of the reductases in the cell that need to reduce their substrates.^ Hundreds of separate types of dehydrogenases remove electrons from their substrates and reduce NAD + into NADH. This reduced form of the coenzyme is then a substrate for any of the reductases in the cell that need to reduce their substrates.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Finally, the acetyl group on the CoA is oxidised to water and carbon dioxide in the citric acid cycle and electron transport chain , releasing the energy that is stored by reducing the coenzyme nicotinamide adenine dinucleotide (NAD + ) into NADH. Digestion .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Nicotinamide adenine dinucleotide exists in two related forms in the cell, NADH and NADPH. The NAD + /NADH form is more important in catabolic reactions, while NADP + /NADPH is used in anabolic reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[16] .Nicotinamide adenine dinucleotide exists in two related forms in the cell, NADH and NADPH. The NAD+/NADH form is more important in catabolic reactions, while NADP+/NADPH is used in anabolic reactions.^ I Intravenous infusion of fructose has been shown to enhance reduced form of nicotinamide adenine dinucleotide reoxidation and, thereby, to enhance the metabolism of ethanol.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

^ Genotyping was performed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method on white cell DNA. Results.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

Structure of hemoglobin. .The protein subunits are in red and blue, and the iron-containing heme groups in green.^ The protein subunits are in red and blue, and the iron-containing heme groups in green.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Bacteria are colored blue, eukaryotes red, and archaea green.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Structure of ATP synthase , the proton channel and rotating stalk are shown in blue and the synthase subunits in red.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

From PDB 1GZX.

Minerals and cofactors

.Inorganic elements play critical roles in metabolism; some are abundant (e.g.^ Further information: Physiology , bioinorganic chemistry and iron metabolism Inorganic elements play critical roles in metabolism; some are abundant (e.g.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The abundant inorganic elements act as ionic electrolytes .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Zinc: The role of zinc in thyroid hormone peripheral metabolism is still being elucidated; however, preliminary evidence suggests this nutrient might play an important role.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

sodium and potassium) while others function at minute concentrations. .About 99% of mammals' mass are the elements carbon, nitrogen, calcium, sodium, chlorine, potassium, hydrogen, phosphorus, oxygen and sulfur.^ Biomolecules consist primarily of carbon and hydrogen, along with nitrogen, oxygen, phosphorus and sulfur.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ About 99% of mammals' mass are the elements carbon , nitrogen , calcium , sodium , chlorine , potassium , hydrogen , oxygen and sulfur .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ For example, muscle contraction depends upon the movement of calcium, sodium and potassium through ion channels in the cell membrane and T-tubules .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[17] .The organic compounds (proteins, lipids and carbohydrates) contain the majority of the carbon and nitrogen and most of the oxygen and hydrogen is present as water.^ The organic compounds (proteins, lipids and carbohydrates) contain the majority of the carbon and nitrogen and most of the oxygen and hydrogen is present as water.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Fatty acids release more energy upon oxidation than carbohydrates because carbohydrates contain more oxygen in their structures.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ This process is often coupled to the conversion of carbon dioxide into organic compounds, as part of photosynthesis, which is discussed below.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[17]
.The abundant inorganic elements act as ionic electrolytes.^ The abundant inorganic elements act as ionic electrolytes .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Further information: Physiology , bioinorganic chemistry and iron metabolism Inorganic elements play critical roles in metabolism; some are abundant (e.g.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

The most important ions are sodium, potassium, calcium, magnesium, chloride, phosphate, and the organic ion bicarbonate. .The maintenance of precise gradients across cell membranes maintains osmotic pressure and pH.^ The substance is moved across the cell membrane by a carrier protein.
  • Biology 100 Practice Challenge Exam I-2007 11 September 2009 8:27 UTC academics.tctc.edu [Source type: Academic]

[18] .Ions are also critical for nerves and muscles, as action potentials in these tissues are produced by the exchange of electrolytes between the extracellular fluid and the cytosol.^ Ions are also critical for nerves and muscles , as action potentials in these tissues are produced by the exchange of electrolytes between the extracellular fluid and the cytosol .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In these experiments, 3,5-T2 exerted its greatest stimulatory effect on brown adipose tissue (BAT), while 3,3'-T2 had its greatest effect on muscle oxidative capacity.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

[19] .Electrolytes enter and leave cells through proteins in the cell membrane called ion channels.^ Electrolytes enter and leave cells through proteins in the cell membrane called ion channels .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ For example, muscle contraction depends upon the movement of calcium, sodium and potassium through ion channels in the cell membrane and T-tubules .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ "Modulation of ion channels in neurons and other cells".
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

For example, muscle contraction depends upon the movement of calcium, sodium and potassium through ion channels in the cell membrane and T-tubules.[20]
The transition metals are usually present as trace elements in organisms, with zinc and iron being most abundant.[21][22] .These metals are used in some proteins as cofactors and are essential for the activity of enzymes such as catalase and oxygen-carrier proteins such as hemoglobin.^ Carrier testing using molecular genetic techniques is possible for some cobalamin disorders.
  • Disorders of Intracellular Cobalamin Metabolism -- GeneReviews -- NCBI Bookshelf 28 January 2010 0:27 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ The role of the deiodinase enzymes in the formation and elimination of the T2 isomers, particularly since some of these isomers appear to have capability for metabolic activity independent of T3, might also play an important metabolic role in some tissues.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

^ It can suggest that these changes may be reflected by enzyme activity in the serum.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

[23] .These cofactors are bound tightly to a specific protein; although enzyme cofactors can be modified during catalysis, cofactors always return to their original state after catalysis has taken place.^ These cofactors are bound tightly to a specific protein; although enzyme cofactors can be modified during catalysis, cofactors always return to their original state after catalysis has taken place.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The amino acids or sugars released by these extracellular enzymes are then pumped into cells by specific active transport proteins.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These metals are used in some proteins as cofactors and are essential for the activity of enzymes such as catalase and oxygen-carrier proteins such as hemoglobin .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.The metal micronutrients are taken up into organisms by specific transporters and bound to storage proteins such as ferritin or metallothionein when not being used.^ When a organism such as a yeast lives by fermentation, it converts the pyruvic acid from glycolysis into a different compound such as alcohol.
  • Biology 100 Practice Challenge Exam I-2007 11 September 2009 8:27 UTC academics.tctc.edu [Source type: Academic]

^ The techniques that are used to join together genes from different sources in a test tube and to insert foreign DNA into an organism's genome are collectively called __________.
  • Biology 100 Practice Challenge Exam I-2007 11 September 2009 8:27 UTC academics.tctc.edu [Source type: Academic]

[24][25]

Catabolism

.Catabolism is the set of metabolic processes that break down large molecules.^ Further information: Catabolism Catabolism is the set of metabolic processes that release energy.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Catabolism is the set of metabolic pathways that break down molecules into smaller units and release energy.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These include breaking down and oxidising food molecules as well as reactions that trap the energy in sunlight.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

These include breaking down and oxidising food molecules. .The purpose of the catabolic reactions is to provide the energy and components needed by anabolic reactions.^ The purpose of these catabolic reactions is to provide the energy and components needed by anabolic reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Further information: Anabolism Anabolism is the set of constructive metabolic processes where the energy released by catabolism is used to synthesize complex molecules.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Nicotinamide adenine dinucleotide exists in two related forms in the cell, NADH and NADPH. The NAD + /NADH form is more important in catabolic reactions, while NADP + /NADPH is used in anabolic reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.The exact nature of these catabolic reactions differ from organism to organism and organisms can be classified based on their sources of energy and carbon (their primary nutritional groups), as shown in the table below.^ These reactions require energy.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Organisms can be further classified by ultimate source of their energy: photoautotrophs and photoheterotrophs obtain energy from light, whereas chemoautotrophs and chemoheterotrophs obtain energy from inorganic oxidation reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The exact nature of these catabolic reactions differ from organism to organism, with organic molecules being used as a source of energy in organotrophs , while lithotrophs use inorganic substrates and phototrophs capture sunlight as chemical energy.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Organic molecules being used as a source of energy in organotrophs, while lithotrophs use inorganic substrates and phototrophs capture sunlight as chemical energy.^ The exact nature of these catabolic reactions differ from organism to organism, with organic molecules being used as a source of energy in organotrophs , while lithotrophs use inorganic substrates and phototrophs capture sunlight as chemical energy.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Organisms can be further classified by ultimate source of their energy: photoautotrophs and photoheterotrophs obtain energy from light, whereas chemoautotrophs and chemoheterotrophs obtain energy from inorganic oxidation reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Further information: Phototroph , photophosphorylation , chloroplast The energy in sunlight is captured by plants , cyanobacteria , purple bacteria , green sulfur bacteria and some protists .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.However, all these different forms of metabolism depend on redox reactions that involve the transfer of electrons from reduced donor molecules such as organic molecules, water, ammonia, hydrogen sulfide or ferrous ions to acceptor molecules such as oxygen, nitrate or sulfate.^ In animals these reactions involve complex organic molecules being broken down to simpler molecules, such as carbon dioxide and water.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ However, all these different forms of metabolism depend on redox reactions that involve the transfer of electrons from reduced donor molecules such as organic molecules , water , ammonia , hydrogen sulfide or ferrous ions to acceptor molecules such as oxygen , nitrate or sulphate .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Lipids are usually defined as hydrophobic or amphipathic biological molecules that will dissolve in organic solvents such as benzene or chloroform .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[26] .In animals these reactions involve complex organic molecules being broken down to simpler molecules, such as carbon dioxide and water.^ Autotrophs such as plants can construct the complex organic molecules in cells such as polysaccharides and proteins from simple molecules like carbon dioxide and water.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In animals these reactions involve complex organic molecules being broken down to simpler molecules, such as carbon dioxide and water.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Many of these microbial reactions are shared with multicellular organisms, but due to their incredible diversity, microbes are able to deal with a far wider range of xenobiotics than multicellular organisms and can degrade even persistent organic pollutants such as organochloride compounds.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.In photosynthetic organisms such as plants and cyanobacteria, these electron-transfer reactions do not release energy, but are used as a way of storing energy absorbed from sunlight.^ This nucleotide is used to transfer chemical energy between different chemical reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In photosynthetic organisms such as plants and cyanobacteria , these electron-transfer reactions do not release energy, but are used as a way of storing energy absorbed from sunlight.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These reactions require energy.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[6]
Classification of organisms based on their metabolism
energy source sunlight photo-   -troph
preformed molecules chemo-
electron donor organic compound   organo-  
inorganic compound litho-
carbon source organic compound   hetero-
inorganic compound auto-
.
The most common set of catabolic reactions in animals can be separated into three main stages.
^ The most common set of catabolic reactions in animals can be separated into three main stages.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ This common chemistry allows cells to use a small set of metabolic intermediates to carry chemical groups between different reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Catabolism is the set of metabolic pathways that break down molecules into smaller units and release energy.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.In the first, large organic molecules such as proteins, polysaccharides or lipids are digested into their smaller components outside cells.^ In the first, large organic molecules such as proteins , polysaccharides or lipids are digested into their smaller components outside cells.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Lipids are usually defined as hydrophobic or amphipathic biological molecules that will dissolve in organic solvents such as benzene or chloroform .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Firstly, the production of precursors such as amino acids , monosaccharides , isoprenoids and nucleotides , secondly, their activation into reactive forms using energy from ATP, and thirdly, the assembly of these precursors into complex molecules such as proteins , polysaccharides , lipids and nucleic acids .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Next, these smaller molecules are taken up by cells and converted to yet smaller molecules, usually acetyl coenzyme A (acetyl-CoA), which releases some energy.^ ACL (ATP-citrate lyase) converts citrate, transported outside the mitochondrion, into acetate (=acetyl CoA).
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

^ Don't save these foods up and add them to the next meal or use them between meals as snacks.

Finally, the acetyl group on the CoA is oxidised to water and carbon dioxide in the citric acid cycle and electron transport chain, releasing the energy that is stored by reducing the coenzyme nicotinamide adenine dinucleotide (NAD+) into NADH.

Digestion

.Macromolecules such as starch, cellulose or proteins cannot be rapidly taken up by cells and need to be broken into their smaller units before they can be used in cell metabolism.^ Clemens DL. Use of cultured cells to study alcohol metabolism.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

^ Such assays rely on the incorporation of radiolabeled precursors into macromolecules.
  • Disorders of Intracellular Cobalamin Metabolism -- GeneReviews -- NCBI Bookshelf 28 January 2010 0:27 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ A predisposition for obesity might be wired into the brain from the start, suggests a new study of rats in the February issue of Cell Metabolism, a publication of Cell Press.

.Several common classes of enzymes digest these polymers.^ Several common classes of enzymes digest these polymers.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Microbes simply secrete digestive enzymes into their surroundings, [28] [29] while animals only secrete these enzymes from specialized cells in their guts .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Both enzymes occur in several forms that are encoded by different genes; moreover, there are variants (i.e., alleles) of some of these genes that encode enzymes with different characteristics and which have different ethnic distributions.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

.These digestive enzymes include proteases that digest proteins into amino acids, as well as glycoside hydrolases that digest polysaccharides into monosaccharides.^ Amino acids and proteins .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These digestive enzymes include proteases that digest proteins into amino acids, as well as glycoside hydrolases that digest polysaccharides into monosaccharides.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These include the sequential addition of novel enzymes to a short ancestral pathway, the duplication and then divergence of entire pathways as well as the recruitment of pre-existing enzymes and their assembly into a novel reaction pathway.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Microbes simply secrete digestive enzymes into their surroundings,[27][28] while animals only secrete these enzymes from specialized cells in their guts.^ Microbes simply secrete digestive enzymes into their surroundings, [28] [29] while animals only secrete these enzymes from specialized cells in their guts .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The amino acids or sugars released by these extracellular enzymes are then pumped into cells by specific active transport proteins.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In animals, glucuronidation is a major thyroid hormone metabolism pathway; however, there are species- 33 and gender-dependent 40 variations in glucuronidation enzyme activity and specificity for thyroid hormones.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

[29] .The amino acids or sugars released by these extracellular enzymes are then pumped into cells by specific active transport proteins.^ The probable lysosomal cobalamin transporter LMBR1 DOMAIN -CONTAINING PROTEIN 1 protein is 540 amino acids and has a predicted molecular weight of 61.3 kd (the longest isoform).
  • Disorders of Intracellular Cobalamin Metabolism -- GeneReviews -- NCBI Bookshelf 28 January 2010 0:27 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ The methylmalonic aciduria and homocystinuria type C protein is 282 amino acids and has a predicted molecular weight of 37.1 kd.
  • Disorders of Intracellular Cobalamin Metabolism -- GeneReviews -- NCBI Bookshelf 28 January 2010 0:27 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ The synthesis of these hormones requires the amino acid tyrosine and the trace mineral iodine.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

[30][31]
A simplified outline of the catabolism of proteins, carbohydrates and fats

Energy from organic compounds

Carbohydrate catabolism is the breakdown of carbohydrates into smaller units. .Carbohydrates are usually taken into cells once they have been digested into monosaccharides.^ Carbohydrates are usually taken into cells once they have been digested into monosaccharides .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Next, these smaller molecules are taken up by cells and converted to yet smaller molecules, usually acetyl coenzyme A (CoA), which releases some energy.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In the first, large organic molecules such as proteins , polysaccharides or lipids are digested into their smaller components outside cells.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[32] .Once inside, the major route of breakdown is glycolysis, where sugars such as glucose and fructose are converted into pyruvate and some ATP is generated.^ Once inside, the major route of breakdown is glycolysis , where sugars such as glucose and fructose are converted into pyruvate and some ATP is generated.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ ACL (ATP-citrate lyase) converts citrate, transported outside the mitochondrion, into acetate (=acetyl CoA).
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

^ Although fat is a common way of storing energy, in vertebrates such as humans the fatty acids in these stores cannot be converted to glucose through gluconeogenesis as these organisms cannot convert acetyl-CoA into pyruvate .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[33] .Pyruvate is an intermediate in several metabolic pathways, but the majority is converted to acetyl-CoA and fed into the citric acid cycle.^ Pyruvate is an intermediate in several metabolic pathways, but the majority is converted to acetyl-CoA and fed into the citric acid cycle .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ ACL (ATP-citrate lyase) converts citrate, transported outside the mitochondrion, into acetate (=acetyl CoA).
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

^ Fatty acid synthase (FAS) is a complex enzyme that converts malonyl CoA (produced from acetyl CoA in the preceeding step in the pathway) into a 16 carbon fatty acid through a series of chemical reactions denoted by the dotted line.
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

.Although some more ATP is generated in the citric acid cycle, the most important product is NADH, which is made from NAD+ as the acetyl-CoA is oxidized.^ ACL (ATP-citrate lyase) converts citrate, transported outside the mitochondrion, into acetate (=acetyl CoA).
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

^ Although some T3 is produced in the thyroid, approximately 80-85 percent is generated outside the thyroid, primarily by conversion of T4 in the liver and kidneys.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

.This oxidation releases carbon dioxide as a waste product.^ A formula was found describing possible arterio-venous shunt accounting for elevated venous pO(2) and enabling calculation of the relevant venous carbon dioxide content and CO2 product.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

.In anaerobic conditions, glycolysis produces lactate, through the enzyme lactate dehydrogenase re-oxidizing NADH to NAD+ for re-use in glycolysis.^ In anaerobic conditions, glycolysis produces lactate , through the enzyme lactate dehydrogenase re-oxidizing NADH to NAD+ for re-use in glycolysis.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Reducing equivalents (NADPH) required for fatty acid biosynthesis are produced from NADP by the enzymes glucose-6-phosphate dehydrogenase, isocitrate dehydrogenase, and malate dehydrogenase .
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

^ In the first one ethanol is oxidized to acetaldehyde by the cytoplasmic alcohol dehydrogenase enzyme (ADH), acetaldehyde is then oxidized to acetic acid by the mitochondrial acetaldehyde dehydrogenase (ALDH).
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

.An alternative route for glucose breakdown is the pentose phosphate pathway, which reduces the coenzyme NADPH and produces pentose sugars such as ribose, the sugar component of nucleic acids.^ An alternative route for glucose breakdown is the pentose phosphate pathway , which reduces the coenzyme NADPH and produces pentose sugars such as ribose , the sugar component of nucleic acids .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Boxes next to triglyceride and phospholipid indicate that these compounds are produced from phosphatidate by removal of the phosphate group (to produce diglyceride) and subsequent addition of (1) a third fatty acid (triglyceride), or (2) a phosphorylated compound such as phosphocholine (phospholipid).
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

^ Anabolism , on the other hand, uses this energy to construct components of cells such as proteins and nucleic acids .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Fats are catabolised by hydrolysis to free fatty acids and glycerol.^ Box under phosphatidate indicates that this compound is composed of two fatty acids (FA) linked to glycerol-3-phosphate.
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

^ Nutritional and hormonal regulation in fat synthesis: Studies of fatty acid synthase and mitochondrial glycerol-3-phosphate acyltransferase gene transcription.
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

^ Of course you need fat, fat is a necessary macronutrient used for hormone production , essential fatty acids, and normal metabolism.

.The glycerol enters glycolysis and the fatty acids are broken down by beta oxidation to release acetyl-CoA, which then is fed into the citric acid cycle.^ Pyruvate is an intermediate in several metabolic pathways, but the majority is converted to acetyl-CoA and fed into the citric acid cycle .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The glycerol enters glycolysis and the fatty acids are broken down by beta oxidation to release acetyl-CoA, which then is fed into the citric acid cycle.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ ACL (ATP-citrate lyase) converts citrate, transported outside the mitochondrion, into acetate (=acetyl CoA).
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

.Fatty acids release more energy upon oxidation than carbohydrates because carbohydrates contain more oxygen in their structures.^ Fatty acids release more energy upon oxidation than carbohydrates because carbohydrates contain more oxygen in their structures.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In plants, photosystem II uses light energy to remove electrons from water, releasing oxygen as a waste product.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Because unchecked Metabolism B effects so much more than weight, living the The Metabolism Miracle lifestyle also improves energy, overall physical health, and emotional well-being.

.Amino acids are either used to synthesize proteins and other biomolecules, or oxidized to urea and carbon dioxide as a source of energy.^ Amino acids and proteins .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Amino acids are either used to synthesize proteins and other biomolecules, or oxidized to urea and carbon dioxide as a source of energy.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Both adenine and guanine are made from the precursor nucleoside inosine monophosphate, which is synthesized using atoms from the amino acids glycine , glutamine , and aspartic acid , as well as formate transferred from the coenzyme tetrahydrofolate .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[34] The oxidation pathway starts with the removal of the amino group by a transaminase. .The amino group is fed into the urea cycle, leaving a deaminated carbon skeleton in the form of a keto acid.^ Rats were thus divided into the following groups: fed-saline (n = 8); fed-ethanol (n = 8); starved 1 day, saline (n = 8); starved 1 day, ethanol (n = 9); starved 2 days, saline (n = 7); and starved 2 days, ethanol (n = 8).
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

.Several of these keto acids are intermediates in the citric acid cycle, for example the deamination of glutamate forms α-ketoglutarate.^ Several of these keto acids are intermediates in the citric acid cycle, for example the deamination of glutamate forms α- ketoglutarate .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The amino group is fed into the urea cycle , leaving a deaminated carbon skeleton in the form of a keto acid .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ He discovered the urea cycle and later, working with Hans Kornberg , the citric acid cycle and the glyoxylate cycle.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[35] .The glucogenic amino acids can also be converted into glucose, through gluconeogenesis (discussed below).^ The glucogenic amino acids can also be converted into glucose, through gluconeogenesis (discussed below).
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Although fat is a common way of storing energy, in vertebrates such as humans the fatty acids in these stores cannot be converted to glucose through gluconeogenesis as these organisms cannot convert acetyl-CoA into pyruvate .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The amino acids or sugars released by these extracellular enzymes are then pumped into cells by specific active transport proteins.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[36]

Energy transformations

Oxidative phosphorylation

.
Structure of ATP synthase.
^ Structure of ATP synthase , the proton channel and rotating stalk are shown in blue and the synthase subunits in red.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

The proton channel and rotating stalk are shown in blue and the synthase subunits in red.
.In oxidative phosphorylation, the electrons removed from food molecules in pathways such as the citric acid cycle are transferred to oxygen and the energy released is used to make ATP. This is done in eukaryotes by a series of proteins in the membranes of mitochondria called the electron transport chain.^ These proteins use the energy released from passing electrons from reduced molecules like NADH onto oxygen to pump protons across a membrane.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Further information: Oxidative phosphorylation , chemiosmosis and mitochondrion In oxidative phosphorylation, the electrons removed from food molecules in pathways such as the citric acid cycle are transferred to oxygen and the energy released used to make ATP. This is done in eukaryotes by a series of proteins in the membranes of mitochondria called the electron transport chain .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The acyl chains in the fatty acids are extended by a cycle of reactions that add the actyl group, reduce it to the alcohol, dehydrate it to an alkene group and then reduce it again to an alkane group.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.In prokaryotes, these proteins are found in the cell's inner membrane.^ In prokaryotes , these proteins are found in the cell's inner membrane .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Prokaryotes (IPA: / prəʊˈkæriəʊtiz /) are a group of organisms that lack a cell nucleus (= karyon), or any other membrane-bound organelles.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The amino acids or sugars released by these extracellular enzymes are then pumped into cells by specific active transport proteins.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[37] .These proteins use the energy released from passing electrons from reduced molecules like NADH onto oxygen to pump protons across a membrane.^ The electrons then flow to the cytochrome b6f complex , which uses their energy to pump protons across the thylakoid membrane in the chloroplast .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These proteins use the energy released from passing electrons from reduced molecules like NADH onto oxygen to pump protons across a membrane.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These organisms can use hydrogen , [41] reduced sulfur compounds (such as sulfide , hydrogen sulfide and thiosulfate ), [42] ferrous iron (FeII) [43] or ammonia [44] as sources of reducing power and they gain energy from the oxidation of these compounds with electron acceptors such as oxygen or nitrite .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[38]
.Pumping protons out of the mitochondria creates a proton concentration difference across the membrane and generates an electrochemical gradient.^ Pumping protons out of the mitochondria creates a proton concentration difference across the membrane and generates a electrochemical gradient .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The electrons then flow to the cytochrome b6f complex , which uses their energy to pump protons across the thylakoid membrane in the chloroplast .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The maintenance of precise gradient s across cell membranes maintains osmotic pressure and pH .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[39] .This force drives protons back into the mitochondrion through the base of an enzyme called ATP synthase.^ ACL (ATP-citrate lyase) converts citrate, transported outside the mitochondrion, into acetate (=acetyl CoA).
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

^ Fatty acid synthase (FAS) is a complex enzyme that converts malonyl CoA (produced from acetyl CoA in the preceeding step in the pathway) into a 16 carbon fatty acid through a series of chemical reactions denoted by the dotted line.
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

^ ATP is synthesized when H+ ions move through a protein port provided by ATP synthase .
  • Biology 100 Practice Challenge Exam I-2007 11 September 2009 8:27 UTC academics.tctc.edu [Source type: Academic]

The flow of protons makes the stalk subunit rotate, causing the active site of the synthase domain to change shape and phosphorylate adenosine diphosphate - turning it into ATP.[14]

Energy from inorganic compounds

Chemolithotrophy is a type of metabolism found in prokaryotes where energy is obtained from the oxidation of inorganic compounds. .These organisms can use hydrogen,[40] reduced sulfur compounds (such as sulfide, hydrogen sulfide and thiosulfate),[1] ferrous iron (FeII)[41] or ammonia[42] as sources of reducing power and they gain energy from the oxidation of these compounds with electron acceptors such as oxygen or nitrite.^ It is not known whether similar effects occur in vivo or whether, if such effects do occur, they are restricted to specific flavonoid compounds or dosages.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

[43] .These microbial processes are important in global biogeochemical cycles such as acetogenesis, nitrification and denitrification and are critical for soil fertility.^ These microbial processes are important in global biogeochemical cycles such as acetogenesis , nitrification and denitrification and are critical for soil fertility .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In ecology , these reactions are particularly important in microbial biodegradation of pollutants and the bioremediation of contaminated land and oil spills.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These molecules are critical for the storage and use of genetic information, through the processes of transcription and protein biosynthesis .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[44][45]

Energy from light

The energy in sunlight is captured by plants, cyanobacteria, purple bacteria, green sulfur bacteria and some protists. .This process is often coupled to the conversion of carbon dioxide into organic compounds, as part of photosynthesis, which is discussed below.^ This process is often coupled to the conversion of carbon dioxide into organic compounds, as part of photosynthesis, which is discussed below.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These differ by the route that carbon dioxide takes to the Calvin cycle, with C3 plants fixing CO 2 directly, while C4 and CAM photosynthesis incorporate the CO 2 into other compounds first, as adaptations to deal with intense sunlight and dry conditions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Autotrophs such as plants can construct the complex organic molecules in cells such as polysaccharides and proteins from simple molecules like carbon dioxide and water.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.The energy capture and carbon fixation systems can however operate separately in prokaryotes, as purple bacteria and green sulfur bacteria can use sunlight as a source of energy, while switching between carbon fixation and the fermentation of organic compounds.^ The energy capture and carbon fixation systems can however operate separately in prokaryotes, as purple bacteria and green sulfur bacteria can use sunlight as a source of energy, while switching between carbon fixation and the fermentation of organic compounds.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Energy from organic compounds .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These organisms can use hydrogen , [41] reduced sulfur compounds (such as sulfide , hydrogen sulfide and thiosulfate ), [42] ferrous iron (FeII) [43] or ammonia [44] as sources of reducing power and they gain energy from the oxidation of these compounds with electron acceptors such as oxygen or nitrite .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[46][47]
.In many organisms the capture of solar energy is similar in principle to oxidative phosphorylation, as it involves energy being stored as a proton concentration gradient and this proton motive force then driving ATP synthesis.^ ATP synthesis driven by light energy .
  • Biology 100 Practice Challenge Exam I-2007 11 September 2009 8:27 UTC academics.tctc.edu [Source type: Academic]

[14] .The electrons needed to drive this electron transport chain come from light-gathering proteins called photosynthetic reaction centres or rhodopsins.^ The electrons needed to drive this electron transport chain come from light-gathering proteins called photosynthetic reaction centres .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Further information: Oxidative phosphorylation , chemiosmosis and mitochondrion In oxidative phosphorylation, the electrons removed from food molecules in pathways such as the citric acid cycle are transferred to oxygen and the energy released used to make ATP. This is done in eukaryotes by a series of proteins in the membranes of mitochondria called the electron transport chain .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In photosynthetic organisms such as plants and cyanobacteria , these electron-transfer reactions do not release energy, but are used as a way of storing energy absorbed from sunlight.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Reaction centers are classed into two types depending on the type of photosynthetic pigment present, with most photosynthetic bacteria only having one type, while plants and cyanobacteria have two.^ These structures are classed into two types depending on the type of photosynthetic pigment present, with most photosynthetic bacteria only having one type of reaction center, while plants and cyanobacteria have two.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Two alcohol dehydrogenase genes (ADH1B and ADH1C on chromosome 4) and one aldehyde dehydrogenase gene (ALDH2 on chromosome 12) exhibit functional polymorpbisms that are associated with lower rates of alcohol dependence.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

^ Most bacteria and plants can synthesize all twenty, but mammals can synthesize only the ten nonessential amino acids.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[48]
.In plants, algae, and cyanobateria, photosystem II uses light energy to remove electrons from water, releasing oxygen as a waste product.^ In plants, photosystem II uses light energy to remove electrons from water, releasing oxygen as a waste product.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The electrons then flow to the cytochrome b6f complex , which uses their energy to pump protons across the thylakoid membrane in the chloroplast .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Fatty acids release more energy upon oxidation than carbohydrates because carbohydrates contain more oxygen in their structures.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

The electrons then flow to the cytochrome b6f complex, which uses their energy to pump protons across the thylakoid membrane in the chloroplast.[6] .These protons move back through the membrane as they drive the ATP synthase, as before.^ This force drives protons back into the mitochondrion through the base of an enzyme called ATP synthase .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These protons move back through the membrane as they drive the ATP synthase, as before.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Structure of ATP synthase , the proton channel and rotating stalk are shown in blue and the synthase subunits in red.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

The electrons then flow through photosystem I and can then either be used to reduce the coenzyme NADP+, for use in the Calvin cycle which is discussed below, or recycled for further ATP generation.[49]

Anabolism

.Anabolism is the set of constructive metabolic processes where the energy released by catabolism is used to synthesize complex molecules.^ For the related metabolic process, see anabolism.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Further information: Anabolism Anabolism is the set of constructive metabolic processes where the energy released by catabolism is used to synthesize complex molecules.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Anabolism is the set of metabolic pathways that construct molecules from smaller units.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.In general, the complex molecules that make up cellular structures are constructed step-by-step from small and simple precursors.^ In general, the complex molecules that make up cellular structures are constructed step-by-step from small and simple precursors.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Further information: Anabolism Anabolism is the set of constructive metabolic processes where the energy released by catabolism is used to synthesize complex molecules.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ As these molecules are vital for life, metabolism focuses on making these molecules, in the construction of cells and tissues, or breaking them down and using them as a source of energy, in the digestion and use of food.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Anabolism involves three basic stages.^ Anabolism involves three basic stages.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Firstly, the production of precursors such as amino acids, monosaccharides, isoprenoids and nucleotides, secondly, their activation into reactive forms using energy from ATP, and thirdly, the assembly of these precursors into complex molecules such as proteins, polysaccharides, lipids and nucleic acids.^ The probable lysosomal cobalamin transporter LMBR1 DOMAIN -CONTAINING PROTEIN 1 protein is 540 amino acids and has a predicted molecular weight of 61.3 kd (the longest isoform).
  • Disorders of Intracellular Cobalamin Metabolism -- GeneReviews -- NCBI Bookshelf 28 January 2010 0:27 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ After the thyroid hormones are formed, lysosomal proteases sever T4 (as well as any T3 or rT3 formed) from the thyroglobulin molecule, and the hormones are released into circulation.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

^ Metabolic screening tests such as urine organic acid analysis and plasma amino acid analysis help to categorize the clinical syndrome.
  • Disorders of Intracellular Cobalamin Metabolism -- GeneReviews -- NCBI Bookshelf 28 January 2010 0:27 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

.Organisms differ in how many of the molecules in their cells they can construct for themselves.^ Organisms differ in how many of the molecules in their cells they can construct for themselves.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ As these molecules are vital for life, metabolism focuses on making these molecules, in the construction of cells and tissues, or breaking them down and using them as a source of energy, in the digestion and use of food.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Autotrophs such as plants can construct the complex organic molecules in cells such as polysaccharides and proteins from simple molecules like carbon dioxide and water.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Autotrophs such as plants can construct the complex organic molecules in cells such as polysaccharides and proteins from simple molecules like carbon dioxide and water.^ Autotrophs such as plants can construct the complex organic molecules in cells such as polysaccharides and proteins from simple molecules like carbon dioxide and water.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In animals these reactions involve complex organic molecules being broken down to simpler molecules, such as carbon dioxide and water.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Overall, these studies give a good view of the structure and function of simple metabolic pathways, but are inadequate when applied to more complex systems such as the metabolism of a complete cell.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Heterotrophs, on the other hand, require a source of more complex substances, such as monosaccharides and amino acids, to produce these complex molecules.^ Heterotrophs , on the other hand, require a source of more complex substances, such as monosaccharides and amino acids, to produce these complex molecules.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Overall, these studies give a good view of the structure and function of simple metabolic pathways, but are inadequate when applied to more complex systems such as the metabolism of a complete cell.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Firstly, the production of precursors such as amino acids , monosaccharides , isoprenoids and nucleotides , secondly, their activation into reactive forms using energy from ATP, and thirdly, the assembly of these precursors into complex molecules such as proteins , polysaccharides , lipids and nucleic acids .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

Organisms can be further classified by ultimate source of their energy: photoautotrophs and photoheterotrophs obtain energy from light, whereas chemoautotrophs and chemoheterotrophs obtain energy from inorganic oxidation reactions.

Carbon fixation

Plant cells (bounded by purple walls) filled with chloroplasts (green), which are the site of photosynthesis
Photosynthesis is the synthesis of carbohydrates from sunlight and carbon dioxide (CO2). In plants, cyanobacteria and algae, oxygenic photosynthesis splits water, with oxygen produced as a waste product. .This process uses the ATP and NADPH produced by the photosynthetic reaction centres, as described above, to convert CO2 into glycerate 3-phosphate, which can then be converted into glucose.^ This process uses the ATP and NADPH produced by the photosynthetic reaction centres , as described above, to convert CO 2 into glycerate 3-phosphate , which can then be converted into glucose.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ ACL (ATP-citrate lyase) converts citrate, transported outside the mitochondrion, into acetate (=acetyl CoA).
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

^ Fatty acid synthase (FAS) is a complex enzyme that converts malonyl CoA (produced from acetyl CoA in the preceeding step in the pathway) into a 16 carbon fatty acid through a series of chemical reactions denoted by the dotted line.
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

.This carbon-fixation reaction is carried out by the enzyme RuBisCO as part of the Calvin – Benson cycle.^ This carbon-fixation reaction is carried out by the enzyme RuBisCO as part of the Calvin – Benson cycle .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Each class of group-transfer reaction is carried out by a particular coenzyme, which is the substrate for a set of enzymes that produce it, and a set of enzymes that consume it.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Type I deiodinase is the major enzyme in the liver, kidneys, and skeletal muscle; it can carry out both 5'- and 5-deiodination of T4 to produce either T3 or rT3.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

[50] Three types of photosynthesis occur in plants, C3 carbon fixation, C4 carbon fixation and CAM photosynthesis. .These differ by the route that carbon dioxide takes to the Calvin cycle, with C3 plants fixing CO2 directly, while C4 and CAM photosynthesis incorporate the CO2 into other compounds first, as adaptations to deal with intense sunlight and dry conditions.^ Three types of photosynthesis occur in plants, C3 carbon fixation , C4 carbon fixation and CAM photosynthesis .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These differ by the route that carbon dioxide takes to the Calvin cycle, with C3 plants fixing CO 2 directly, while C4 and CAM photosynthesis incorporate the CO 2 into other compounds first, as adaptations to deal with intense sunlight and dry conditions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Here, carbon dioxide can be fixed by the Calvin – Benson cycle, a reversed citric acid cycle, [55] or the carboxylation of acetyl-CoA. [56] [57] Prokaryotic chemoautotrophs also fix CO 2 through the Calvin – Benson cycle, but use energy from inorganic compounds to drive the reaction.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[51]
.In photosynthetic prokaryotes the mechanisms of carbon fixation are more diverse.^ In photosynthetic prokaryotes the mechanisms of carbon fixation are more diverse.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Here, carbon dioxide can be fixed by the Calvin – Benson cycle, a reversed citric acid cycle,[52] or the carboxylation of acetyl-CoA.[53][54] Prokaryotic chemoautotrophs also fix CO2 through the Calvin – Benson cycle, but use energy from inorganic compounds to drive the reaction.^ Here, carbon dioxide can be fixed by the Calvin – Benson cycle, a reversed citric acid cycle, [55] or the carboxylation of acetyl-CoA. [56] [57] Prokaryotic chemoautotrophs also fix CO 2 through the Calvin – Benson cycle, but use energy from inorganic compounds to drive the reaction.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Organisms can be further classified by ultimate source of their energy: photoautotrophs and photoheterotrophs obtain energy from light, whereas chemoautotrophs and chemoheterotrophs obtain energy from inorganic oxidation reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These differ by the route that carbon dioxide takes to the Calvin cycle, with C3 plants fixing CO 2 directly, while C4 and CAM photosynthesis incorporate the CO 2 into other compounds first, as adaptations to deal with intense sunlight and dry conditions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[55]

Carbohydrates and glycans

.In carbohydrate anabolism, simple organic acids can be converted into monosaccharides such as glucose and then used to assemble polysaccharides such as starch.^ Metabolic screening tests such as urine organic acid analysis and plasma amino acid analysis help to categorize the clinical syndrome.
  • Disorders of Intracellular Cobalamin Metabolism -- GeneReviews -- NCBI Bookshelf 28 January 2010 0:27 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ Histograms refer to the mean (±SEM) amount of injected 14 C-palmitic acid converted into 14 C-CO 2 during the standard four-hour incubation period.
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

^ Metabolic screening tests such as urine organic acid analysis and plasma amino acid analysis help categorize the clinical syndrome.
  • Disorders of Intracellular Cobalamin Metabolism -- GeneReviews -- NCBI Bookshelf 28 January 2010 0:27 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

.The generation of glucose from compounds like pyruvate, lactate, glycerol, glycerate 3-phosphate and amino acids is called gluconeogenesis.^ The generation of glucose from compounds like pyruvate , lactate , glycerol , glycerate 3-phosphate and amino acids is called gluconeogenesis .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Although fat is a common way of storing energy, in vertebrates such as humans the fatty acids in these stores cannot be converted to glucose through gluconeogenesis as these organisms cannot convert acetyl-CoA into pyruvate .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In biochemistry, this term refers to alpha-amino acids with the general formula H 2 NCHRCOOH, where R is an organic substituent.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

Gluconeogenesis converts pyruvate to glucose-6-phosphate through a series of intermediates, many of which are shared with glycolysis.[33] .However, this pathway is not simply glycolysis run in reverse, as several steps are catalyzed by non-glycolytic enzymes.^ However, this pathway is not simply glycolysis run in reverse, as several steps are catalyzed by non-glycolytic enzymes.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In animals, glucuronidation is a major thyroid hormone metabolism pathway; however, there are species- 33 and gender-dependent 40 variations in glucuronidation enzyme activity and specificity for thyroid hormones.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

.This is important as it allows the formation and breakdown of glucose to be regulated separately and prevents both pathways from running simultaneously in a futile cycle.^ This is important as it allows the formation and breakdown of glucose to be regulated separately and prevents both pathways from running simultaneously in a futile cycle .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ An alternative route for glucose breakdown is the pentose phosphate pathway , which reduces the coenzyme NADPH and produces pentose sugars such as ribose , the sugar component of nucleic acids .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[56][57]
.Although fat is a common way of storing energy, in vertebrates such as humans the fatty acids in these stores cannot be converted to glucose through gluconeogenesis as these organisms cannot convert acetyl-CoA into pyruvate; plants do, but animals do not, have the necessary enzymatic machinery.^ Although fat is a common way of storing energy, in vertebrates such as humans the fatty acids in these stores cannot be converted to glucose through gluconeogenesis as these organisms cannot convert acetyl-CoA into pyruvate .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The glucogenic amino acids can also be converted into glucose, through gluconeogenesis (discussed below).
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ ACL (ATP-citrate lyase) converts citrate, transported outside the mitochondrion, into acetate (=acetyl CoA).
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

[58] .As a result, after long-term starvation, vertebrates need to produce ketone bodies from fatty acids to replace glucose in tissues such as the brain that cannot metabolize fatty acids.^ Metabolic screening tests such as urine organic acid analysis and plasma amino acid analysis help to categorize the clinical syndrome.
  • Disorders of Intracellular Cobalamin Metabolism -- GeneReviews -- NCBI Bookshelf 28 January 2010 0:27 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ By living The Metabolism Miracle Lifestyle, you finally have the long-term weight loss solution that will actually help mend your body and soul!

^ Exposure to toxic metals such as cadmium or lead can result in an alteration in peripheral metabolism of thyroid hormones.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

[59] .In other organisms such as plants and bacteria, this metabolic problem is solved using the glyoxylate cycle, which bypasses the decarboxylation step in the citric acid cycle and allows the transformation of acetyl-CoA to oxaloacetate, where it can be used for the production of glucose.^ In other organisms such as plants and bacteria, this metabolic problem is solved using the glyoxylate cycle , which bypasses the decarboxylation step in the citric acid cycle and allows the transformation of acetyl-CoA to oxaloacetate , where it can be used for the production of glucose.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The retention of these ancient pathways during later evolution may be the result of these reactions being an optimal solution to their particular metabolic problems, with pathways such as glycolysis and the citric acid cycle producing their end products highly efficiently and in a minimal number of steps.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Here, organisms such as yeast , plants or bacteria are genetically-modified to make them more useful in biotechnology and aid the production of drugs such as antibiotics or industrial chemicals such as 1,3-propanediol and shikimic acid .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[58][60]
.Polysaccharides and glycans are made by the sequential addition of monosaccharides by glycosyltransferase from a reactive sugar-phosphate donor such as uridine diphosphate glucose (UDP-glucose) to an acceptor hydroxyl group on the growing polysaccharide.^ Polysaccharides and glycans are made by the sequential addition of monosaccharides by glycosyltransferase from a reactive sugar-phosphate donor such as uridine diphosphate glucose (UDP-glucose) to an acceptor hydroxyl group on the growing polysaccharide.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Several variations on this basic structure exist, including alternate backbones such as sphingosine in the sphingolipids , and hydrophilic groups such as phosphate in phospholipids .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Further information: Gluconeogenesis , glyoxylate cycle , glycogenesis and glycosylation In carbohydrate anabolism, simple organic acids can be converted into monosaccharides such as glucose and then used to assemble polysaccharides such as starch .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.As any of the hydroxyl groups on the ring of the substrate can be acceptors, the polysaccharides produced can have straight or branched structures.^ As any of the hydroxyl groups on the ring of the substrate can be acceptors, the polysaccharides produced can have straight or branched structures.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Polysaccharides and glycans are made by the sequential addition of monosaccharides by glycosyltransferase from a reactive sugar-phosphate donor such as uridine diphosphate glucose (UDP-glucose) to an acceptor hydroxyl group on the growing polysaccharide.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Each class of group-transfer reaction is carried out by a particular coenzyme, which is the substrate for a set of enzymes that produce it, and a set of enzymes that consume it.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[61] .The polysaccharides produced can have structural or metabolic functions themselves, or be transferred to lipids and proteins by enzymes called oligosaccharyltransferases.^ Hepatic antioxidant enzyme systems and lipid peroxidation have shown a consistent association with peripheral metabolism of thyroid hormones in animal models.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

^ Results: COMT Val158Met is a common (minor allele frequency 0.42), functional, catecholamine-metabolizing enzyme polymorphism with threefold relevance.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

^ Global alterations of lipid metabolism, most likely produced by alterations in endocrine regulation, underlie morph specializations for flight vs. G. firmus .
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

[62][63]

Fatty acids, isoprenoids and steroids

.
Simplified version of the steroid synthesis pathway with the intermediates isopentenyl pyrophosphate (IPP), dimethylallyl pyrophosphate (DMAPP), geranyl pyrophosphate (GPP) and squalene shown.
^ Further information: Fatty acid synthesis , mevalonate pathway and non-mevalonate pathway Simplified version of the steroid synthesis pathway with the intermediates isopentenyl pyrophosphate (IPP), dimethylallyl pyrophosphate (DMAPP), geranyl pyrophosphate (GPP) and squalene shown.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These compounds are made by the assembly and modification of isoprene units donated from the reactive precursors isopentenyl pyrophosphate and dimethylallyl pyrophosphate .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

Some intermediates are omitted for clarity.
.Fatty acids are made by fatty acid synthases that polymerize and then reduce acetyl-CoA units.^ Fatty acids are made by fatty acid synthases that polymerize and reduce acetyl-CoA units.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The acyl chains in the fatty acids are extended by a cycle of reactions that add the actyl group, reduce it to the alcohol, dehydrate it to an alkene group and then reduce it again to an alkane group.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Although fat is a common way of storing energy, in vertebrates such as humans the fatty acids in these stores cannot be converted to glucose through gluconeogenesis as these organisms cannot convert acetyl-CoA into pyruvate .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.The acyl chains in the fatty acids are extended by a cycle of reactions that add the actyl group, reduce it to an alcohol, dehydrate it to an alkene group and then reduce it again to an alkane group.^ The acyl chains in the fatty acids are extended by a cycle of reactions that add the actyl group, reduce it to the alcohol, dehydrate it to an alkene group and then reduce it again to an alkane group.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ "The puzzle of the Krebs citric acid cycle: assembling the pieces of chemically feasible reactions, and opportunism in the design of metabolic pathways during evolution".
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Reducing equivalents (NADPH) required for fatty acid biosynthesis are produced from NADP by the enzymes glucose-6-phosphate dehydrogenase, isocitrate dehydrogenase, and malate dehydrogenase .
  • Intermediary Metabolism and Life History Trade-offs: Lipid Metabolism in Lines of the Wing-polymorphic Cricket, Gryllus firmus, Selected for Flight Capability vs. Early Age Reproduction -- Zera 45 (3): 511 -- Integrative and Comparative Biology 28 January 2010 0:27 UTC icb.oxfordjournals.org [Source type: Academic]

.The enzymes of fatty acid biosynthesis are divided into two groups, in animals and fungi all these fatty acid synthase reactions are carried out by a single multifunctional type I protein,[64] while in plant plastids and bacteria separate type II enzymes perform each step in the pathway.^ "Structure and function of animal fatty acid synthase".
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ "The structural biology of type II fatty acid biosynthesis".
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The enzymes of fatty acid biosynthesis are divided into two groups, in animals and fungi all these fatty acid synthase reactions are carried out by a single multifunctional type I protein, [67] while in plant plastids and bacteria separate type II enzymes perform each step in the pathway.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[65][66]
Terpenes and isoprenoids are a large class of lipids that include the carotenoids and form the largest class of plant natural products.[67] .These compounds are made by the assembly and modification of isoprene units donated from the reactive precursors isopentenyl pyrophosphate and dimethylallyl pyrophosphate.^ These compounds are made by the assembly and modification of isoprene units donated from the reactive precursors isopentenyl pyrophosphate and dimethylallyl pyrophosphate .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These precursors can be made in different ways.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[68] .These precursors can be made in different ways.^ These precursors can be made in different ways.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Sometimes mistakes are made when this happens and the resulting new cell or virus is different in some way.

^ These compounds are made by the assembly and modification of isoprene units donated from the reactive precursors isopentenyl pyrophosphate and dimethylallyl pyrophosphate .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.In animals and archaea, the mevalonate pathway produces these compounds from acetyl-CoA,[69] while in plants and bacteria the non-mevalonate pathway uses pyruvate and glyceraldehyde 3-phosphate as substrates.^ An overview of the non-mevalonate pathway for terpenoid biosynthesis in plants ".
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In animals and archaea, the mevalonate pathway produces these compounds from acetyl-CoA, [72] while in plants and bacteria the non-mevalonate pathway uses pyruvate and glyceraldehyde 3-phosphate as substrates.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Although fat is a common way of storing energy, in vertebrates such as humans the fatty acids in these stores cannot be converted to glucose through gluconeogenesis as these organisms cannot convert acetyl-CoA into pyruvate .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[68][70] .One important reaction that uses these activated isoprene donors is steroid biosynthesis.^ July 19, 2009......One Reader's Story This is a very "real" email that I received regarding one very important use of The Metabolism Miracle .

.Here, the isoprene units are joined together to make squalene and then folded up and formed into a set of rings to make lanosterol.^ Here, the isoprene units are joined together to make squalene and then folded up and formed into a set of rings to make lanosterol .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The techniques that are used to join together genes from different sources in a test tube and to insert foreign DNA into an organism's genome are collectively called __________.
  • Biology 100 Practice Challenge Exam I-2007 11 September 2009 8:27 UTC academics.tctc.edu [Source type: Academic]

^ Catabolism is the set of metabolic pathways that break down molecules into smaller units and release energy.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[71] .Lanosterol can then be converted into other steroids such as cholesterol and ergosterol.^ Lanosterol can then be converted into other steroids such as cholesterol and ergosterol .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Steroids such as cholesterol are another major class of lipids that are made in cells.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Once inside, the major route of breakdown is glycolysis , where sugars such as glucose and fructose are converted into pyruvate and some ATP is generated.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[71][72]

Proteins

.Organisms vary in their ability to synthesize the 20 common amino acids.^ Further information: Protein biosynthesis , Amino acid synthesis Organisms vary in their ability to synthesize the 20 common amino acids.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Amino acids are either used to synthesize proteins and other biomolecules, or oxidized to urea and carbon dioxide as a source of energy.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Most bacteria and plants can synthesize all twenty, but mammals can synthesize only the ten nonessential amino acids.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Most bacteria and plants can synthesize all twenty, but mammals can synthesize only the ten nonessential amino acids.^ Most bacteria and plants can synthesize all twenty, but mammals can synthesize only the ten nonessential amino acids.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These structures are classed into two types depending on the type of photosynthetic pigment present, with most photosynthetic bacteria only having one type of reaction center, while plants and cyanobacteria have two.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Most of the structures that make up animals, plants and microbes are made from three basic classes of molecule: amino acids , carbohydrates and lipids (often called fats ).
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[6] .Thus, the essential amino acids must be obtained from food.^ Thus, the essential amino acids must be obtained from food.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ For example, in some parasites metabolic processes that are not essential for survival are lost and preformed amino acids, nucleotides and carbohydrates may instead be scavenged from the host .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

All amino acids are synthesized from intermediates in glycolysis, the citric acid cycle, or the pentose phosphate pathway. .Nitrogen is provided by glutamate and glutamine.^ Nitrogen is provided by glutamate and glutamine .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Amino acid synthesis depends on the formation of the appropriate alpha-keto acid, which is then transaminated to form an amino acid.^ Amino acid synthesis depends on the formation of the appropriate alpha-keto acid, which is then transaminated to form an amino acid.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In biochemistry, this term refers to alpha-amino acids with the general formula H 2 NCHRCOOH, where R is an organic substituent.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Several of these keto acids are intermediates in the citric acid cycle, for example the deamination of glutamate forms α- ketoglutarate .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[73]
.Amino acids are made into proteins by being joined together in a chain by peptide bonds.^ Amino acids and proteins .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Proteins are large organic compounds made of amino acids arranged in a linear chain and joined together by peptide bonds between the carboxyl and amino groups of adjacent amino acid residues.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Proteins are made of amino acids arranged in a linear chain and joined together by peptide bonds .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Each different protein has a unique sequence of amino acid residues: this is its primary structure.^ Translation would continue, but the second amino acid in the protein would be different.
  • Biology 100 Practice Challenge Exam I-2007 11 September 2009 8:27 UTC academics.tctc.edu [Source type: Academic]

^ The probable lysosomal cobalamin transporter LMBR1 DOMAIN -CONTAINING PROTEIN 1 protein is 540 amino acids and has a predicted molecular weight of 61.3 kd (the longest isoform).
  • Disorders of Intracellular Cobalamin Metabolism -- GeneReviews -- NCBI Bookshelf 28 January 2010 0:27 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ The methylmalonic aciduria and homocystinuria type C protein is 282 amino acids and has a predicted molecular weight of 37.1 kd.
  • Disorders of Intracellular Cobalamin Metabolism -- GeneReviews -- NCBI Bookshelf 28 January 2010 0:27 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

.Just as the letters of the alphabet can be combined to form an almost endless variety of words, amino acids can be linked in varying sequences to form a huge variety of proteins.^ Amino acids and proteins .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Just as the letters of the alphabet can be combined to form an almost endless variety of words, amino acids can be linked in varying sequences to form a huge variety of proteins.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The amino acids or sugars released by these extracellular enzymes are then pumped into cells by specific active transport proteins.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Proteins are made from amino acids that have been activated by attachment to a transfer RNA molecule through an ester bond.^ Amino acids and proteins .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Proteins are made from amino acids that have been activated by attachment to a transfer RNA molecule through an ester bond.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Both adenine and guanine are made from the precursor nucleoside inosine monophosphate, which is synthesized using atoms from the amino acids glycine , glutamine , and aspartic acid , as well as formate transferred from the coenzyme tetrahydrofolate .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.This aminoacyl-tRNA precursor is produced in an ATP-dependent reaction carried out by an aminoacyl tRNA synthetase.^ This aminoacyl-tRNA precursor is produced in an ATP -dependent reaction carried out by an aminoacyl tRNA synthetase .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ This carbon-fixation reaction is carried out by the enzyme RuBisCO as part of the Calvin – Benson cycle .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Each class of group-transfer reaction is carried out by a particular coenzyme, which is the substrate for a set of enzymes that produce it, and a set of enzymes that consume it.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[74] .This aminoacyl-tRNA is then a substrate for the ribosome, which joins the amino acid onto the elongating protein chain, using the sequence information in a messenger RNA.^ The probable lysosomal cobalamin transporter LMBR1 DOMAIN -CONTAINING PROTEIN 1 protein is 540 amino acids and has a predicted molecular weight of 61.3 kd (the longest isoform).
  • Disorders of Intracellular Cobalamin Metabolism -- GeneReviews -- NCBI Bookshelf 28 January 2010 0:27 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ The methylmalonic aciduria and homocystinuria type C protein is 282 amino acids and has a predicted molecular weight of 37.1 kd.
  • Disorders of Intracellular Cobalamin Metabolism -- GeneReviews -- NCBI Bookshelf 28 January 2010 0:27 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ Hypomethioninemia and homocystinemia and mixed disulfide can be detected using plasma amino acid analysis (see Table 3 ).
  • Disorders of Intracellular Cobalamin Metabolism -- GeneReviews -- NCBI Bookshelf 28 January 2010 0:27 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

[75]

Nucleotide synthesis and salvage

.Nucleotides are made from amino acids, carbon dioxide and formic acid in pathways that require large amounts of metabolic energy.^ Further information: Nucleotide salvage , Pyrimidine biosynthesis , and Purine metabolism Nucleotides are made from amino acids, carbon dioxide and formic acid in pathways that require large amounts of metabolic energy.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Proteins are large organic compounds made of amino acids arranged in a linear chain and joined together by peptide bonds between the carboxyl and amino groups of adjacent amino acid residues.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Pyruvate is an intermediate in several metabolic pathways, but the majority is converted to acetyl-CoA and fed into the citric acid cycle .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[76] Consequently, most organisms have efficient systems to salvage preformed nucleotides.[76][77] Purines are synthesized as nucleosides (bases attached to ribose). .Both adenine and guanine are made from the precursor nucleoside inosine monophosphate, which is synthesized using atoms from the amino acids glycine, glutamine, and aspartic acid, as well as formate transferred from the coenzyme tetrahydrofolate.^ Both adenine and guanine are made from the precursor nucleoside inosine monophosphate, which is synthesized using atoms from the amino acids glycine , glutamine , and aspartic acid , as well as formate transferred from the coenzyme tetrahydrofolate .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Proteins are made from amino acids that have been activated by attachment to a transfer RNA molecule through an ester bond.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Proteins are made of amino acids arranged in a linear chain and joined together by peptide bonds .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Pyrimidines, on the other hand, are synthesized from the base orotate, which is formed from glutamine and aspartate.^ Pyrimidines , on the other hand, are synthesized from the base orotate , which is formed from glutamine and aspartate.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[78]

Xenobiotics and redox metabolism

.All organisms are constantly exposed to compounds that they cannot use as foods and would be harmful if they accumulated in cells, as they have no metabolic function.^ Further information: Detoxification , Drug metabolism and Antioxidants All organisms are constantly exposed to compounds that they cannot use as foods and would be harmful if they accumulated in cells, as they have no metabolic function.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ This common chemistry allows cells to use a small set of metabolic intermediates to carry chemical groups between different reactions.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Extrinsic control involves a cell in a multicellular organism changing its metabolism in response to signals from other cells.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.These potentially damaging compounds are called xenobiotics.^ These potentially damaging compounds are called xenobiotics .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These effects are believed to be secondary to the severe liver damage this compound causes.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

[79] .Xenobiotics such as synthetic drugs, natural poisons and antibiotics are detoxified by a set of xenobiotic-metabolizing enzymes.^ Since zinc is not a cofactor in hepatic type I-deiodinase enzyme, the nature of zinc's influence on aspects of peripheral metabolism in animals and humans remains unclear.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

^ Enzyme activity can be modulated by numerous foreign compounds, such as common chemicals and drugs.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

^ Flavonoids, both naturally occurring and synthetic derivatives, have the potential to disrupt thyroid hormone metabolism in vitro.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

.In humans, these include cytochrome P450 oxidases,[80] UDP-glucuronosyltransferases,[81] and glutathione S-transferases.^ It shares 38% sequence identity with human cytochrome P450 reductase [ Leclerc et al 1998 ].
  • Disorders of Intracellular Cobalamin Metabolism -- GeneReviews -- NCBI Bookshelf 28 January 2010 0:27 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

[82] .This system of enzymes acts in three stages to firstly oxidize the xenobiotic (phase I) and then conjugate water-soluble groups onto the molecule (phase II).^ This system of enzymes acts in three stages to firstly oxidize the xenobiotic (phase I) and then conjugate water-soluble groups onto the molecule (phase II).
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The modified water-soluble xenobiotic can then be pumped out of cells and in multicellular organisms may be further metabolized before being excreted (phase III).
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The fats are a large group of compounds that contain fatty acids and glycerol ; a glycerol molecule attached to three fatty acid esters is a triacylglyceride .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.The modified water-soluble xenobiotic can then be pumped out of cells and in multicellular organisms may be further metabolized before being excreted (phase III).^ The modified water-soluble xenobiotic can then be pumped out of cells and in multicellular organisms may be further metabolized before being excreted (phase III).
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Extrinsic control involves a cell in a multicellular organism changing its metabolism in response to signals from other cells.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In human nutrition , most vitamins function as coenzymes after modification; for example, all water-soluble vitamins are phosphorylated or are coupled to nucleotides when they are used in cells.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

In ecology, these reactions are particularly important in microbial biodegradation of pollutants and the bioremediation of contaminated land and oil spills.[83] Many of these microbial reactions are shared with multicellular organisms, but due to the incredible diversity of types of microbes these organisms are able to deal with a far wider range of xenobiotics than multicellular organisms, and can degrade even persistent organic pollutants such as organochloride compounds.[84]
.A related problem for aerobic organisms is oxidative stress.^ "Oxidative stress: the paradox of aerobic life".
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ A related problem for aerobic organisms is oxidative stress .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[85] .Here, processes including oxidative phosphorylation and the formation of disulfide bonds during protein folding produce reactive oxygen species such as hydrogen peroxide.^ Here, processes including oxidative phosphorylation and the formation of disulfide bonds during protein folding produce reactive oxygen species such as hydrogen peroxide .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The organic compounds (proteins, lipids and carbohydrates) contain the majority of the carbon and nitrogen and most of the oxygen and hydrogen is present as water.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Further information: Oxidative phosphorylation , chemiosmosis and mitochondrion In oxidative phosphorylation, the electrons removed from food molecules in pathways such as the citric acid cycle are transferred to oxygen and the energy released used to make ATP. This is done in eukaryotes by a series of proteins in the membranes of mitochondria called the electron transport chain .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[86] .These damaging oxidants are removed by antioxidant metabolites such as glutathione and enzymes such as catalases and peroxidases.^ Antioxidant enzyme systems, including superoxide dismutase 26,28 and catalase,28 are also reduced subsequent to exposure.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

^ These transformations are all catalyzed by deiodination enzymes which remove iodine atoms from the inner tyrosyl or outer phenolic benzene rings.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

^ At these higher doses, T4 and hepatic lipid peroxidase were increased and hepatic catalase and super oxide dismutase antioxidant enzyme systems and T3 concentrations decreased.
  • Thyroid Metabolism 28 January 2010 0:27 UTC www.chiro.org [Source type: Academic]

[87][88]

Thermodynamics of living organisms

.Living organisms must obey the laws of thermodynamics, which describe the transfer of heat and work.^ Further information: Biological thermodynamics Living organisms must obey the laws of thermodynamics , which describe the transfer of heat and work .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Thermodynamics of living organisms .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Although living organisms' amazing complexity appears to contradict this law, life is possible as all organisms are open system s that exchange matter and energy with their surroundings.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

The second law of thermodynamics states that in any closed system, the amount of entropy (disorder) will tend to increase. .Although living organisms' amazing complexity appears to contradict this law, life is possible as all organisms are open systems that exchange matter and energy with their surroundings.^ Although living organisms' amazing complexity appears to contradict this law, life is possible as all organisms are open system s that exchange matter and energy with their surroundings.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Thus living systems are not in equilibrium , but instead are dissipative systems that maintain their state of high complexity by causing a larger increase in the entropy of their environments.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Further information: Molecular evolution and Phylogenetics Evolutionary tree showing the common ancestry of organisms from all three domains of life.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Thus living systems are not in equilibrium, but instead are dissipative systems that maintain their state of high complexity by causing a larger increase in the entropy of their environments.^ Thus living systems are not in equilibrium , but instead are dissipative systems that maintain their state of high complexity by causing a larger increase in the entropy of their environments.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Although living organisms' amazing complexity appears to contradict this law, life is possible as all organisms are open system s that exchange matter and energy with their surroundings.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The second law of thermodynamics states that in any closed system , the amount of entropy (disorder) will tend to increase.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[89] .The metabolism of a cell achieves this by coupling the spontaneous processes of catabolism to the non-spontaneous processes of anabolism.^ The metabolism of a cell achieves this by coupling the spontaneous processes of catabolism to the non-spontaneous processes of anabolism.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ For the related metabolic process, see anabolism.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ One way of categorizing metabolic processes, whether at the cellular, organ or organism level is as 'anabolic' or 'catabolic', which is the opposite.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

In thermodynamic terms, metabolism maintains order by creating disorder.[90]

Regulation and control

.As the environments of most organisms are constantly changing, the reactions of metabolism must be finely regulated to maintain a constant set of conditions within cells, a condition called homeostasis.^ Metabolism is the complete set of chemical reactions that occur in living cells .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Further information: Metabolic pathway , metabolic control analysis , hormone and cell signaling As the environments of most organisms are constantly changing, the reactions of metabolism must be finely regulated to maintain a constant set of conditions within cells, a condition called homeostasis .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Extrinsic control involves a cell in a multicellular organism changing its metabolism in response to signals from other cells.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[91][92] Metabolic regulation also allows organisms to respond to signals and interact actively with their environments.[93] .Two closely linked concepts are important for understanding how metabolic pathways are controlled.^ Two closely-linked concepts are important for understanding how metabolic pathways are controlled.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Ethanol is mainly metabolized in the liver by two oxidative pathways.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

.Firstly, the regulation of an enzyme in a pathway is how its activity is increased and decreased in response to signals.^ Firstly, the regulation of an enzyme in a pathway is how its activity is increased and decreased in response to signals.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In intrinsic regulation, the metabolic pathway self-regulates to respond to changes in the levels of substrates or products; for example, a decrease in the amount of product can increase the flux through the pathway to compensate.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ This type of regulation often involves allosteric regulation of the activities of multiple enzymes in the pathway.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Secondly, the control exerted by this enzyme is the effect that these changes in its activity have on the overall rate of the pathway (the flux through the pathway).^ It can suggest that these changes may be reflected by enzyme activity in the serum.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

^ Secondly, the control exerted by this enzyme is the effect that these changes in its activity have on the overall rate of the pathway (the flux through the pathway).
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Also, there may be sex differences in the effect of these enzyme genotypes on glucose metabolism.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

[94] .For example, an enzyme may show large changes in activity (i.e. it is highly regulated) but if these changes have little effect on the flux of a metabolic pathway, then this enzyme is not involved in the control of the pathway.^ Also, there may be sex differences in the effect of these enzyme genotypes on glucose metabolism.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

^ It can suggest that these changes may be reflected by enzyme activity in the serum.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

^ CYP2E1 is an important enzyme involved in the brain metabolism of ethanol that can be induced by chronic consumption of alcohol.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

[95]
.
Effect of insulin on glucose uptake and metabolism. Insulin binds to its receptor (1) which in turn starts many protein activation cascades (2).
^ Effect of insulin on glucose uptake and metabolism.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Insulin binds to its receptor (1) which in turn starts many protein activation cascades (2).
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Binding of the hormone to insulin receptors on cells then activates a cascade of protein kinases that cause the cells to take up glucose and convert it into storage molecules such as fatty acids and glycogen .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

These include: translocation of Glut-4 transporter to the plasma membrane and influx of glucose (3), glycogen synthesis (4), glycolysis (5) and fatty acid synthesis (6).
.There are multiple levels of metabolic regulation.^ There are multiple levels of metabolic regulation.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In intrinsic regulation, the metabolic pathway self-regulates to respond to changes in the levels of substrates or products; for example, a decrease in the amount of product can increase the flux through the pathway to compensate.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Metabolic Disorders Metabolic disorders are rare and occur when there is an abnormal level of a particular body chemical (either enzymes or substances) or a malfunctioning in the metabolic process.
  • Types of Metabolic Disorders - Natural Metabolism Boosters 28 January 2010 0:27 UTC www.nativeremedies.com [Source type: FILTERED WITH BAYES]

.In intrinsic regulation, the metabolic pathway self-regulates to respond to changes in the levels of substrates or products; for example, a decrease in the amount of product can increase the flux through the pathway to compensate.^ In intrinsic regulation, the metabolic pathway self-regulates to respond to changes in the levels of substrates or products; for example, a decrease in the amount of product can increase the flux through the pathway to compensate.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ There are multiple levels of metabolic regulation.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Swift increase in alcohol metabolism is an excellent example of the complexity of cell-cell interactions in liver and extrahepatic regulation of biochemical and molecular events in this organ, and this important phenomenon shall be considered in studies of liver disease and biochemistry.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

[94] .This type of regulation often involves allosteric regulation of the activities of multiple enzymes in the pathway.^ This type of regulation often involves allosteric regulation of the activities of multiple enzymes in the pathway.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Recent findings: Metabolism of ethanol changes with advancing age because activity of the enzymes involved, such as alcohol and acetalclehyde dehydrogenase and cytochrome P-4502E1, diminish with age.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

^ Enzymes also allow the regulation of metabolic pathways in response to changes in the cell's environment or signals from other cells.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[96] .Extrinsic control involves a cell in a multicellular organism changing its metabolism in response to signals from other cells.^ Extrinsic control involves a cell in a multicellular organism changing its metabolism in response to signals from other cells.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Enzymes also allow the regulation of metabolic pathways in response to changes in the cell's environment or signals from other cells.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Further information: Metabolic pathway , metabolic control analysis , hormone and cell signaling As the environments of most organisms are constantly changing, the reactions of metabolism must be finely regulated to maintain a constant set of conditions within cells, a condition called homeostasis .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

These signals are usually in the form of soluble messengers such as hormones and growth factors and are detected by specific receptors on the cell surface.[97] .These signals are then transmitted inside the cell by second messenger systems that often involved the phosphorylation of proteins.^ These signals are then transmitted inside the cell by second messenger systems that often involved the phosphorylation of proteins.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Extrinsic control involves a cell in a multicellular organism changing its metabolism in response to signals from other cells.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Other proteins have structural or mechanical functions, such as the proteins in the cytoskeleton that form a system of scaffolding to maintain cell shape.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[98]
.A very well understood example of extrinsic control is the regulation of glucose metabolism by the hormone insulin.^ A significantly higher first-pass metabolism of ethanol was obtained after administration of fructose in comparison with findings for control experiments with an equimolar dose of glucose.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

^ It can be caused by uncontrolled Metabolism B! The hallmark of Met B is a hormonal imalance of the fat gain hormone, insulin.

^ A: As you know, Metabolism B is progressive and is always driven by a hormonal imbalance of the fat gain hormone, insulin.

[99] .Insulin is produced in response to rises in blood glucose levels.^ Insulin is produced in response to rises in blood glucose levels .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ If blood sugar rises too high from improper dosing of, say, insulin, dehydration occurs.

^ If you have Met B, this rise in blood sugar will make your insulin situation even worse!.I didn’t have anything to wear to work.

.Binding of the hormone to insulin receptors on cells then activates a cascade of protein kinases that cause the cells to take up glucose and convert it into storage molecules such as fatty acids and glycogen.^ Fatty acid ethyl esters (FAEE), non-oxidative metabolites of ethanol, have been shown to be toxic to cells in vitro and in vivo.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

[100] .The metabolism of glycogen is controlled by activity of phosphorylase, the enzyme that breaks down glycogen, and glycogen synthase, the enzyme that makes it.^ Recent findings: Metabolism of ethanol changes with advancing age because activity of the enzymes involved, such as alcohol and acetalclehyde dehydrogenase and cytochrome P-4502E1, diminish with age.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

^ These dramatic changes in rates of alcohol metabolism and tissue concentrations of oxygen are not due to induced enzyme activity in liver.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

.These enzymes are regulated in a reciprocal fashion, with phosphorylation inhibiting glycogen synthase, but activating phosphorylase.^ These enzymes are regulated in a reciprocal fashion, with phosphorylation inhibiting glycogen synthase, but activating phosphorylase.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The metabolism of glycogen is controlled by activity of phosphorylase , the enzyme that breaks down glycogen, and glycogen synthase , the enzyme that makes it.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Insulin causes glycogen synthesis by activating protein phosphatase s and producing a decrease in the phosphorylation of these enzymes.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Insulin causes glycogen synthesis by activating protein phosphatases and producing a decrease in the phosphorylation of these enzymes.^ Insulin causes glycogen synthesis by activating protein phosphatase s and producing a decrease in the phosphorylation of these enzymes.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The amino acids or sugars released by these extracellular enzymes are then pumped into cells by specific active transport proteins.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These cofactors are bound tightly to a specific protein; although enzyme cofactors can be modified during catalysis, cofactors always return to their original state after catalysis has taken place.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[101]

Evolution

.
Evolutionary tree showing the common ancestry of organisms from all three domains of life.
^ Further information: Molecular evolution and Phylogenetics Evolutionary tree showing the common ancestry of organisms from all three domains of life.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Although living organisms' amazing complexity appears to contradict this law, life is possible as all organisms are open system s that exchange matter and energy with their surroundings.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The central pathways of metabolism described above, such as glycolysis and the citric acid cycle, are present in all three domains of living things and were present in the last universal ancestor .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Bacteria are colored blue, eukaryotes red, and archaea green.^ I like to use the analogy of looking at an MRI. Inactive tissue may show up in the color blue whereas active tissue may show up in the color red.

Relative positions of some of the phyla included are shown around the tree.
.The central pathways of metabolism described above, such as glycolysis and the citric acid cycle, are present in all three domains of living things and were present in the last universal ancestor.^ The central pathways of metabolism described above, such as glycolysis and the citric acid cycle, are present in all three domains of living things and were present in the last universal ancestor .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ All amino acids are synthesized from intermediates in glycolysis, the citric acid cycle, or the pentose phosphate pathway.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The retention of these ancient pathways during later evolution may be the result of these reactions being an optimal solution to their particular metabolic problems, with pathways such as glycolysis and the citric acid cycle producing their end products highly efficiently and in a minimal number of steps.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[2][102] .This universal ancestral cell was prokaryotic and probably a methanogen that had extensive amino acid, nucleotide, carbohydrate and lipid metabolism.^ The probable lysosomal cobalamin transporter LMBR1 DOMAIN -CONTAINING PROTEIN 1 protein is 540 amino acids and has a predicted molecular weight of 61.3 kd (the longest isoform).
  • Disorders of Intracellular Cobalamin Metabolism -- GeneReviews -- NCBI Bookshelf 28 January 2010 0:27 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ Metabolic screening tests such as urine organic acid analysis and plasma amino acid analysis help to categorize the clinical syndrome.
  • Disorders of Intracellular Cobalamin Metabolism -- GeneReviews -- NCBI Bookshelf 28 January 2010 0:27 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ Metabolic screening tests such as urine organic acid analysis and plasma amino acid analysis help categorize the clinical syndrome.
  • Disorders of Intracellular Cobalamin Metabolism -- GeneReviews -- NCBI Bookshelf 28 January 2010 0:27 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

[103][104] .The retention of these ancient pathways during later evolution may be the result of these reactions being an optimal solution to their particular metabolic problems, with pathways such as glycolysis and the citric acid cycle producing their end products highly efficiently and in a minimal number of steps.^ "The puzzle of the Krebs citric acid cycle: assembling the pieces of chemically feasible reactions, and opportunism in the design of metabolic pathways during evolution".
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The evolution of organisms can also produce the loss of metabolic pathways.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ "Evolution of carbohydrate metabolic pathways".
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[3][4] .The first pathways of enzyme-based metabolism may have been parts of purine nucleotide metabolism, with previous metabolic pathways being part of the ancient RNA world.^ The first pathways of enzyme-based metabolism may have been parts of purine nucleotide metabolism, with previous metabolic pathways being part of the ancient RNA world .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The retention of these ancient pathways during later evolution may be the result of these reactions being an optimal solution to their particular metabolic problems, with pathways such as glycolysis and the citric acid cycle producing their end products highly efficiently and in a minimal number of steps.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The modified water-soluble xenobiotic can then be pumped out of cells and in multicellular organisms may be further metabolized before being excreted (phase III).
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[105]
.Many models have been proposed to describe the mechanisms by which novel metabolic pathways evolve.^ Many models have been proposed to describe the mechanisms by which novel metabolic pathways evolve.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The relative importance of these mechanisms is unclear, but genomic studies have shown that enzymes in a pathway are likely to have a shared ancestry, suggesting that many pathways have evolved in a step-by-step fashion with novel functions being created from pre-existing steps in the pathway.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The central pathways of metabolism described above, such as glycolysis and the citric acid cycle, are present in all three domains of living things and were present in the last universal ancestor .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.These include the sequential addition of novel enzymes to a short ancestral pathway, the duplication and then divergence of entire pathways as well as the recruitment of pre-existing enzymes and their assembly into a novel reaction pathway.^ These include genes for enzymes involved in alcohol metabolism (alcohol dehydrogenase and aldehyde dehydrogenase), and genes for receptors affected by alcohol (particularly gamma-aminobutyric acid receptors).
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

^ In addition, our results also demonstrated that this risk was associated with significant gene-gene interactions between ADH2 and ALDH2 polymorphisms, as well as gene-environment interactions between these polymorphisms and alcohol drinking.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

[106] .The relative importance of these mechanisms is unclear, but genomic studies have shown that enzymes in a pathway are likely to have a shared ancestry, suggesting that many pathways have evolved in a step-by-step fashion with novel functions being created from pre-existing steps in the pathway.^ The relative importance of these mechanisms is unclear, but genomic studies have shown that enzymes in a pathway are likely to have a shared ancestry, suggesting that many pathways have evolved in a step-by-step fashion with novel functions being created from pre-existing steps in the pathway.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Many models have been proposed to describe the mechanisms by which novel metabolic pathways evolve.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Overall, these studies give a good view of the structure and function of simple metabolic pathways, but are inadequate when applied to more complex systems such as the metabolism of a complete cell.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[107] .An alternative model comes from studies that trace the evolution of proteins' structures in metabolic networks, this has suggested that enzymes are pervasively recruited, borrowing enzymes to perform similar functions in different metabolic pathways (evident in the MANET database)[108] These recruitment processes result in an evolutionary enzymatic mosaic.^ A metabolic network in the evolutionary context: multiscale structure and modularity ".
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ "Evolution of carbohydrate metabolic pathways".
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ "Evolution of enzymes in metabolism: a network perspective".
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[109] .A third possibility is that some parts of metabolism might exist as "modules" that can be reused in different pathways and perform similar functions on different molecules.^ Another possibility is that some parts of metabolism might exist as "modules" that can be reused in different pathways and perform similar functions on different molecules.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The first pathways of enzyme-based metabolism may have been parts of purine nucleotide metabolism, with previous metabolic pathways being part of the ancient RNA world .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ A striking feature of metabolism is the similarity of the basic metabolic pathways between even vastly different species.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[110]
.As well as the evolution of new metabolic pathways, evolution can also cause the loss of metabolic functions.^ The evolution of organisms can also produce the loss of metabolic pathways.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ "Evolution of carbohydrate metabolic pathways".
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ "The puzzle of the Krebs citric acid cycle: assembling the pieces of chemically feasible reactions, and opportunism in the design of metabolic pathways during evolution".
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.For example, in some parasites metabolic processes that are not essential for survival are lost and preformed amino acids, nucleotides and carbohydrates may instead be scavenged from the host.^ Metabolic screening tests such as urine organic acid analysis and plasma amino acid analysis help to categorize the clinical syndrome.
  • Disorders of Intracellular Cobalamin Metabolism -- GeneReviews -- NCBI Bookshelf 28 January 2010 0:27 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ Some drugs affect carbohydrate metabolism or glucose counterregulation.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

^ After a period of time, your metabolic rate actually slows to match the deprivation and when you return to normal eating, you regain all that you lost and then some.

[111] .Similar reduced metabolic capabilities are seen in endosymbiotic organisms.^ Similar reduced metabolic capabilities are seen in endosymbiotic organisms.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[112]

Investigation and manipulation

.
Metabolic network of the Arabidopsis thaliana citric acid cycle.
^ Further information: Protein methods , proteomics , metabolomics and metabolic network modelling Metabolic network of the Arabidopsis thaliana citric acid cycle .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ He discovered the urea cycle and later, working with Hans Kornberg , the citric acid cycle and the glyoxylate cycle.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Pyruvate is an intermediate in several metabolic pathways, but the majority is converted to acetyl-CoA and fed into the citric acid cycle .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

Enzymes and metabolites are shown as red squares and the interactions between them as black lines.
.Classically, metabolism is studied by a reductionist approach that focuses on a single metabolic pathway.^ Classically, metabolism is studied by a reductionist approach that focuses on a single metabolic pathway.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ However, numerous metabolomic approaches may contribute to alcohol-related research, as illustrated by studies on alcohol-related metabolic dysfunctions such as (1) alterations in fat metabolism and (2) thiamine deficiency.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

^ Metabolomics -- a systems biology approach to characterizing metabolites produced in biochemical pathways -- is contributing to many studies of disease progression and treatment, although it has not yet been extensively applied in research on metabolic perturbations associated with alcohol abuse.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

.Particularly valuable is the use of radioactive tracers at the whole-organism, tissue and cellular levels, which define the paths from precursors to final products by identifying radioactively labelled intermediates and products.^ Thus, the setup is more valuable for scanning ADH expression at protein level in different tissues and under different conditions, and maybe not as a tool for classification.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

^ Now.......there are two meaningless terms being used on this pasta label....."digestible carb" and "protected carbs" Below is the actual label information from this product: .

[113] The enzymes that catalyze these chemical reactions can then be purified and their kinetics and responses to inhibitors investigated. .A parallel approach is to identify the small molecules in a cell or tissue; the complete set of these molecules is called the metabolome.^ A parallel approach is to identify the small molecules in a cell or tissue; the complete set of these molecules is called the metabolome .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ As these molecules are vital for life, metabolism focuses on making these molecules, in the construction of cells and tissues, or breaking them down and using them as a source of energy, in the digestion and use of food.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In these early studies, the mechanisms of these metabolic processes had not been identified and a vital force was thought to animate living tissue.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Overall, these studies give a good view of the structure and function of simple metabolic pathways, but are inadequate when applied to more complex systems such as the metabolism of a complete cell.^ Overall, these studies give a good view of the structure and function of simple metabolic pathways, but are inadequate when applied to more complex systems such as the metabolism of a complete cell.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The relative importance of these mechanisms is unclear, but genomic studies have shown that enzymes in a pathway are likely to have a shared ancestry, suggesting that many pathways have evolved in a step-by-step fashion with novel functions being created from pre-existing steps in the pathway.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Swift increase in alcohol metabolism is an excellent example of the complexity of cell-cell interactions in liver and extrahepatic regulation of biochemical and molecular events in this organ, and this important phenomenon shall be considered in studies of liver disease and biochemistry.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

[114]
.An idea of the complexity of the metabolic networks in cells that contain thousands of different enzymes is given by the figure showing the interactions between just 43 proteins and 40 metabolites to the right: the sequences of genomes provide lists containing anything up to 45,000 genes.^ An idea of the complexity of the metabolic networks in cells that contain thousands of different enzymes is given by the figure showing the interactions between just 43 proteins and 40 metabolites to the right: the sequences of genomes provide lists containing anything up to 45,000 genes.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ "From genomes to in silico cells via metabolic networks".
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ "Evolution of enzymes in metabolism: a network perspective".
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[115] .However, it is now possible to use this genomic data to reconstruct complete networks of biochemical reactions and produce more holistic mathematical models that may explain and predict their behavior.^ Results: Gender, parental alcohol use and acculturation significantly predicted drinking behavior.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

^ Finally, chronic use or abuse of drugs may lead to behavioral changes, such as irregular eating habits, which may increase the risk of severe hypoglycemia.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

[116] .These models are especially powerful when used to integrate the pathway and metabolite data obtained through classical methods with data on gene expression from proteomic and DNA microarray studies.^ DNA cloning, gene localization, and expression.
  • Disorders of Intracellular Cobalamin Metabolism -- GeneReviews -- NCBI Bookshelf 28 January 2010 0:27 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ Always check the source of funding for the “study” as the money trail often influences the outcome, portrayal of data, and the “media attention” the results obtain.

^ Association studies provide a powerful approach to link DNA variants and genetic predisposition to complex diseases.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

[117] .Using these techniques, a model of human metabolism has now been produced, which will guide future drug discovery and biochemical research.^ However, it is now possible to use this genomic data to reconstruct complete networks of biochemical reactions and produce more holistic mathematical models that may explain and predict their behavior.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Pharmacokinetic models for ethanol metabolism have contributed to the understanding of ethanol clearance in human beings.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

^ Advances in analytical and computational techniques have facilitated the rise of new and powerful tools for measuring metabolic and biochemical pathways in such complex systems.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

[118] .These models are now being used in network analysis, to classify human diseases into groups that share common proteins or metabolites.^ However, it is now possible to use this genomic data to reconstruct complete networks of biochemical reactions and produce more holistic mathematical models that may explain and predict their behavior.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Although fat is a common way of storing energy, in vertebrates such as humans the fatty acids in these stores cannot be converted to glucose through gluconeogenesis as these organisms cannot convert acetyl-CoA into pyruvate .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These models are especially powerful when used to integrate the pathway and metabolite data obtained through classical methods with data on gene expression from proteomic and DNA microarray studies.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[119][120]
.A major technological application of this information is metabolic engineering.^ A major technological application of this information is metabolic engineering .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.Here, organisms such as yeast, plants or bacteria are genetically modified to make them more useful in biotechnology and aid the production of drugs such as antibiotics or industrial chemicals such as 1,3-propanediol and shikimic acid.^ Here, organisms such as yeast , plants or bacteria are genetically-modified to make them more useful in biotechnology and aid the production of drugs such as antibiotics or industrial chemicals such as 1,3-propanediol and shikimic acid .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In other organisms such as plants and bacteria, this metabolic problem is solved using the glyoxylate cycle , which bypasses the decarboxylation step in the citric acid cycle and allows the transformation of acetyl-CoA to oxaloacetate , where it can be used for the production of glucose.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In plants, photosystem II uses light energy to remove electrons from water, releasing oxygen as a waste product.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[121] .These genetic modifications usually aim to reduce the amount of energy used to produce the product, increase yields and reduce the production of wastes.^ These genetic modifications usually aim to reduce the amount of energy used to produce the product, increase yields and reduce the production of wastes.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ In plants, photosystem II uses light energy to remove electrons from water, releasing oxygen as a waste product.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ As these molecules are vital for life, metabolism focuses on making these molecules, in the construction of cells and tissues, or breaking them down and using them as a source of energy, in the digestion and use of food.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[122]

History

Santorio Santorio in his steelyard balance, from Ars de statica medecina, first published 1614
.The term metabolism is derived from the Greek Μεταβολισμός – "Metabolismos" for "change", or "overthrow".[123] The history of the scientific study of metabolism spans several centuries and has moved from examining whole animals in early studies, to examining individual metabolic reactions in modern biochemistry.^ The history of the scientific study of metabolism spans 400 years and has moved from examining whole animals in early studies, to examining individual metabolic reactions in modern biochemistry.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Further information: History of biochemistry and History of molecular biology Santorio Santorio in his steelyard balance, from Ars de statica medecina , first published 1614 The term metabolism is derived from the Greek Μεταβολισμός – "Metabolismos" for "change", or "overthrow".
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ It was the discovery of enzymes at the beginning of the 20th century by Eduard Buchner that separated the study of the chemical reactions of metabolism from the biological study of cells, and marked the beginnings of biochemistry .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

The concept of metabolism dates back to Ibn al-Nafis (1213-1288), who stated that "the body and its parts are in a continuous state of dissolution and nourishment, so they are inevitably undergoing permanent change."[124] The first controlled experiments in human metabolism were published by Santorio Santorio in 1614 in his book Ars de statica medecina.[125] .He described how he weighed himself before and after eating, sleep, working, sex, fasting, drinking, and excreting.^ He described how he weighed himself before and after eating, sleeping, working, sex, fasting, drinking, and excreting.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

He found that most of the food he took in was lost through what he called "insensible perspiration".
.In these early studies, the mechanisms of these metabolic processes had not been identified and a vital force was thought to animate living tissue.^ In these early studies, the mechanisms of these metabolic processes had not been identified and a vital force was thought to animate living tissue.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ The hypothesized mechanism underlying the associations of the ADH1B and ALDH2 polymorphisms with alcohol dependence is that the isoenzymes encoded by these alleles lead to an accumulation of acetaldehyde during alcohol metabolism.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

^ The history of the scientific study of metabolism spans 400 years and has moved from examining whole animals in early studies, to examining individual metabolic reactions in modern biochemistry.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[126] In the 19th century, when studying the fermentation of sugar to alcohol by yeast, Louis Pasteur concluded that fermentation was catalyzed by substances within the yeast cells he called "ferments". He wrote that "alcoholic fermentation is an act correlated with the life and organization of the yeast cells, not with the death or putrefaction of the cells."[127] This discovery, along with the publication by Friedrich Wöhler in 1828 of the chemical synthesis of urea,[128] proved that the organic compounds and chemical reactions found in cells were no different in principle than any other part of chemistry.
.It was the discovery of enzymes at the beginning of the 20th century by Eduard Buchner that separated the study of the chemical reactions of metabolism from the biological study of cells, and marked the beginnings of biochemistry.^ Swift increase in alcohol metabolism is an excellent example of the complexity of cell-cell interactions in liver and extrahepatic regulation of biochemical and molecular events in this organ, and this important phenomenon shall be considered in studies of liver disease and biochemistry.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

^ In this study, we determined the genotype and allelic frequencies of genes encoding enzymes involved in alcohol metabolism in alcoholic and nonalcoholic subjects of related ethnicity.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

^ Clemens DL. Use of cultured cells to study alcohol metabolism.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

[129] .The mass of biochemical knowledge grew rapidly throughout the early 20th century.^ The mass of biochemical knowledge grew rapidly throughout the early 20th century.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

.One of the most prolific of these modern biochemists was Hans Krebs who made huge contributions to the study of metabolism.^ However, numerous metabolomic approaches may contribute to alcohol-related research, as illustrated by studies on alcohol-related metabolic dysfunctions such as (1) alterations in fat metabolism and (2) thiamine deficiency.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

^ These patients most likely did not know that they had Metabolism B. As long as their "pouch" held 2-4 ounces, they were okay.

^ Various factors may contribute to the development (i.e., pathogenesis) of alcohol-associated cancer, including the actions of acetaldehyde, the first and most toxic metabolite of alcohol metabolism.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

[130] .He discovered the urea cycle and later, working with Hans Kornberg, the citric acid cycle and the glyoxylate cycle.^ He discovered the urea cycle and later, working with Hans Kornberg , the citric acid cycle and the glyoxylate cycle.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Pyruvate is an intermediate in several metabolic pathways, but the majority is converted to acetyl-CoA and fed into the citric acid cycle .
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ "The puzzle of the Krebs citric acid cycle: assembling the pieces of chemically feasible reactions, and opportunism in the design of metabolic pathways during evolution".
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

[131][60] .Modern biochemical research has been greatly aided by the development of new techniques such as chromatography, X-ray diffraction, NMR spectroscopy, radioisotopic labelling, electron microscopy and molecular dynamics simulations.^ Modern biochemical research has been greatly aided by the development of new techniques such as chromatography , X-ray diffraction , NMR spectroscopy , radioisotopic labelling , electron microscopy and molecular dynamics simulations.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Volume IV: Modern Development of the Chemical and Biological Sciences Harper and Brothers (New York) Retrieved on 2007-03-26 124.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Advances in analytical and computational techniques have facilitated the rise of new and powerful tools for measuring metabolic and biochemical pathways in such complex systems.
  • CORK Bibliography: Alcohol Metabolism 28 January 2010 0:27 UTC www.projectcork.org [Source type: Academic]

.These techniques have allowed the discovery and detailed analysis of the many molecules and metabolic pathways in cells.^ These techniques have allowed the discovery and detailed analysis of the many molecules and metabolic pathways in cells.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ Overall, these studies give a good view of the structure and function of simple metabolic pathways, but are inadequate when applied to more complex systems such as the metabolism of a complete cell.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

^ These processes are the basis of life , allowing cells to grow and reproduce, maintain their structures, and respond to their environments.
  • What is Metabolism? 28 January 2010 0:27 UTC ipedia.net [Source type: Academic]

See also

References

  1. ^ a b Friedrich C (1998). "Physiology and genetics of sulfur-oxidizing bacteria". Adv Microb Physiol 39: 235–89. doi:10.1016/S0065-2911(08)60018-1. PMID 9328649.  
  2. ^ a b Smith E, Morowitz H (2004). "Universality in intermediary metabolism". Proc Natl Acad Sci USA 101 (36): 13168–73. doi:10.1073/pnas.0404922101. PMID 15340153. PMC 516543. http://www.pnas.org/cgi/pmidlookup?view=long&pmid=15340153.  
  3. ^ a b Ebenhöh O, Heinrich R (2001). "Evolutionary optimization of metabolic pathways. Theoretical reconstruction of the stoichiometry of ATP and NADH producing systems". Bull Math Biol 63 (1): 21–55. doi:10.1006/bulm.2000.0197. PMID 11146883.  
  4. ^ a b Meléndez-Hevia E, Waddell T, Cascante M (1996). "The puzzle of the Krebs citric acid cycle: assembling the pieces of chemically feasible reactions, and opportunism in the design of metabolic pathways during evolution". J Mol Evol 43 (3): 293–303. doi:10.1007/BF02338838. PMID 8703096.  
  5. ^ Michie K, Löwe J (2006). "Dynamic filaments of the bacterial cytoskeleton". Annu Rev Biochem 75: 467–92. doi:10.1146/annurev.biochem.75.103004.142452. PMID 16756499.  
  6. ^ a b c d e f g Nelson, David L.; Michael M. Cox (2005). Lehninger Principles of Biochemistry. New York: W. H. Freeman and company. pp. 841. ISBN 0-7167-4339-6.  
  7. ^ Fahy E, Subramaniam S, Brown H, Glass C, Merrill A, Murphy R, Raetz C, Russell D, Seyama Y, Shaw W, Shimizu T, Spener F, van Meer G, VanNieuwenhze M, White S, Witztum J, Dennis E (2005). "A comprehensive classification system for lipids". J Lipid Res 46 (5): 839–61. doi:10.1194/jlr.E400004-JLR200. PMID 15722563. http://www.jlr.org/cgi/content/full/46/5/839.  
  8. ^ "Nomenclature of Lipids". IUPAC-IUB Commission on Biochemical Nomenclature (CBN). http://www.chem.qmul.ac.uk/iupac/lipid/. Retrieved 2007-03-08.  
  9. ^ Hegardt F (1999). "Mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase: a control enzyme in ketogenesis". Biochem J 338 (Pt 3): 569–82. doi:10.1042/0264-6021:3380569. PMID 10051425.  
  10. ^ Raman R, Raguram S, Venkataraman G, Paulson J, Sasisekharan R (2005). "Glycomics: an integrated systems approach to structure-function relationships of glycans". Nat Methods 2 (11): 817–24. doi:10.1038/nmeth807. PMID 16278650.  
  11. ^ Sierra S, Kupfer B, Kaiser R (2005). "Basics of the virology of HIV-1 and its replication". J Clin Virol 34 (4): 233–44. doi:10.1016/j.jcv.2005.09.004. PMID 16198625.  
  12. ^ a b Wimmer M, Rose I (1978). "Mechanisms of enzyme-catalyzed group transfer reactions". Annu Rev Biochem 47: 1031–78. doi:10.1146/annurev.bi.47.070178.005123. PMID 354490.  
  13. ^ Mitchell P (1979). "The Ninth Sir Hans Krebs Lecture. Compartmentation and communication in living systems. Ligand conduction: a general catalytic principle in chemical, osmotic and chemiosmotic reaction systems". Eur J Biochem 95 (1): 1–20. doi:10.1111/j.1432-1033.1979.tb12934.x. PMID 378655.  
  14. ^ a b c d Dimroth P, von Ballmoos C, Meier T (March 2006). "Catalytic and mechanical cycles in F-ATP synthases. Fourth in the Cycles Review Series". EMBO Rep 7 (3): 276–82. doi:10.1038/sj.embor.7400646. PMID 16607397.  
  15. ^ Coulston, Ann; Kerner, John; Hattner, JoAnn; Srivastava, Ashini (2006). "Nutrition Principles and Clinical Nutrition". Stanford School of Medicine Nutrition Courses. SUMMIT.  
  16. ^ Pollak N, Dölle C, Ziegler M (2007). "The power to reduce: pyridine nucleotides—small molecules with a multitude of functions". Biochem J 402 (2): 205–18. doi:10.1042/BJ20061638. PMID 17295611.  
  17. ^ a b Heymsfield S, Waki M, Kehayias J, Lichtman S, Dilmanian F, Kamen Y, Wang J, Pierson R (1991). "Chemical and elemental analysis of humans in vivo using improved body composition models". Am J Physiol 261 (2 Pt 1): E190–8. PMID 1872381.  
  18. ^ Sychrová H (2004). "Yeast as a model organism to study transport and homeostasis of alkali metal cations" (PDF). Physiol Res 53 Suppl 1: S91–8. PMID 15119939. http://www.biomed.cas.cz/physiolres/pdf/53%20Suppl%201/53_S91.pdf.  
  19. ^ Levitan I (1988). "Modulation of ion channels in neurons and other cells". Annu Rev Neurosci 11: 119–36. doi:10.1146/annurev.ne.11.030188.001003. PMID 2452594.  
  20. ^ Dulhunty A (2006). "Excitation-contraction coupling from the 1950s into the new millennium". Clin Exp Pharmacol Physiol 33 (9): 763–72. doi:10.1111/j.1440-1681.2006.04441.x. PMID 16922804.  
  21. ^ Mahan D, Shields R (1998). "Macro- and micromineral composition of pigs from birth to 145 kilograms of body weight". J Anim Sci 76 (2): 506–12. PMID 9498359. http://jas.fass.org/cgi/reprint/76/2/506.  
  22. ^ Husted S, Mikkelsen B, Jensen J, Nielsen N (2004). "Elemental fingerprint analysis of barley (Hordeum vulgare) using inductively coupled plasma mass spectrometry, isotope-ratio mass spectrometry, and multivariate statistics". Anal Bioanal Chem 378 (1): 171–82. doi:10.1007/s00216-003-2219-0. PMID 14551660.  
  23. ^ Finney L, O'Halloran T (2003). "Transition metal speciation in the cell: insights from the chemistry of metal ion receptors". Science 300 (5621): 931–6. doi:10.1126/science.1085049. PMID 12738850.  
  24. ^ Cousins R, Liuzzi J, Lichten L (2006). "Mammalian zinc transport, trafficking, and signals". J Biol Chem 281 (34): 24085–9. doi:10.1074/jbc.R600011200. PMID 16793761. http://www.jbc.org/cgi/content/full/281/34/24085.  
  25. ^ Dunn L, Rahmanto Y, Richardson D (2007). "Iron uptake and metabolism in the new millennium". Trends Cell Biol 17 (2): 93–100. doi:10.1016/j.tcb.2006.12.003. PMID 17194590.  
  26. ^ Nealson K, Conrad P (1999). "Life: past, present and future". Philos Trans R Soc Lond B Biol Sci 354 (1392): 1923–39. doi:10.1098/rstb.1999.0532. PMID 10670014. PMC 1692713. http://rstb.royalsocietypublishing.org/cgi/pmidlookup?view=long&pmid=10670014.  
  27. ^ Häse C, Finkelstein R (December 1993). "Bacterial extracellular zinc-containing metalloproteases". Microbiol Rev 57 (4): 823–37. PMID 8302217. PMC 372940. http://mmbr.asm.org/cgi/pmidlookup?view=long&pmid=8302217.  
  28. ^ Gupta R, Gupta N, Rathi P (2004). "Bacterial lipases: an overview of production, purification and biochemical properties". Appl Microbiol Biotechnol 64 (6): 763–81. doi:10.1007/s00253-004-1568-8. PMID 14966663.  
  29. ^ Hoyle T (1997). "The digestive system: linking theory and practice". Br J Nurs 6 (22): 1285–91. PMID 9470654.  
  30. ^ Souba W, Pacitti A (1992). "How amino acids get into cells: mechanisms, models, menus, and mediators". JPEN J Parenter Enteral Nutr 16 (6): 569–78. doi:10.1177/0148607192016006569. PMID 1494216.  
  31. ^ Barrett M, Walmsley A, Gould G (1999). "Structure and function of facilitative sugar transporters". Curr Opin Cell Biol 11 (4): 496–502. doi:10.1016/S0955-0674(99)80072-6. PMID 10449337.  
  32. ^ Bell G, Burant C, Takeda J, Gould G (1993). "Structure and function of mammalian facilitative sugar transporters". J Biol Chem 268 (26): 19161–4. PMID 8366068.  
  33. ^ a b Bouché C, Serdy S, Kahn C, Goldfine A (2004). "The cellular fate of glucose and its relevance in type 2 diabetes". Endocr Rev 25 (5): 807–30. doi:10.1210/er.2003-0026. PMID 15466941. http://edrv.endojournals.org/cgi/content/full/25/5/807.  
  34. ^ Sakami W, Harrington H (1963). "Amino acid metabolism". Annu Rev Biochem 32: 355–98. doi:10.1146/annurev.bi.32.070163.002035. PMID 14144484.  
  35. ^ Brosnan J (2000). "Glutamate, at the interface between amino acid and carbohydrate metabolism". J Nutr 130 (4S Suppl): 988S–90S. PMID 10736367. http://jn.nutrition.org/cgi/content/full/130/4/988S.  
  36. ^ Young V, Ajami A (2001). "Glutamine: the emperor or his clothes?". J Nutr 131 (9 Suppl): 2449S–59S; discussion 2486S–7S. PMID 11533293. http://jn.nutrition.org/cgi/content/full/131/9/2449S.  
  37. ^ Hosler J, Ferguson-Miller S, Mills D (2006). "Energy transduction: proton transfer through the respiratory complexes". Annu Rev Biochem 75: 165–87. doi:10.1146/annurev.biochem.75.062003.101730. PMID 16756489.  
  38. ^ Schultz B, Chan S (2001). "Structures and proton-pumping strategies of mitochondrial respiratory enzymes". Annu Rev Biophys Biomol Struct 30: 23–65. doi:10.1146/annurev.biophys.30.1.23. PMID 11340051.  
  39. ^ Capaldi R, Aggeler R (2002). "Mechanism of the F(1)F(0)-type ATP synthase, a biological rotary motor". Trends Biochem Sci 27 (3): 154–60. doi:10.1016/S0968-0004(01)02051-5. PMID 11893513.  
  40. ^ Friedrich B, Schwartz E (1993). "Molecular biology of hydrogen utilization in aerobic chemolithotrophs". Annu Rev Microbiol 47: 351–83. doi:10.1146/annurev.mi.47.100193.002031. PMID 8257102.  
  41. ^ Weber K, Achenbach L, Coates J (2006). "Microorganisms pumping iron: anaerobic microbial iron oxidation and reduction". Nat Rev Microbiol 4 (10): 752–64. doi:10.1038/nrmicro1490. PMID 16980937.  
  42. ^ Jetten M, Strous M, van de Pas-Schoonen K, Schalk J, van Dongen U, van de Graaf A, Logemann S, Muyzer G, van Loosdrecht M, Kuenen J (1998). "The anaerobic oxidation of ammonium". FEMS Microbiol Rev 22 (5): 421–37. doi:10.1111/j.1574-6976.1998.tb00379.x. PMID 9990725.  
  43. ^ Simon J (2002). "Enzymology and bioenergetics of respiratory nitrite ammonification". FEMS Microbiol Rev 26 (3): 285–309. doi:10.1111/j.1574-6976.2002.tb00616.x. PMID 12165429.  
  44. ^ Conrad R (1996). "Soil microorganisms as controllers of atmospheric trace gases (H2, CO, CH4, OCS, N2O, and NO)". Microbiol Rev 60 (4): 609–40. PMID 8987358. PMC 239458. http://mmbr.asm.org/cgi/pmidlookup?view=long&pmid=8987358.  
  45. ^ Barea J, Pozo M, Azcón R, Azcón-Aguilar C (2005). "Microbial co-operation in the rhizosphere". J Exp Bot 56 (417): 1761–78. doi:10.1093/jxb/eri197. PMID 15911555. http://jxb.oxfordjournals.org/cgi/content/full/56/417/1761.  
  46. ^ van der Meer M, Schouten S, Bateson M, Nübel U, Wieland A, Kühl M, de Leeuw J, Sinninghe Damsté J, Ward D (July 2005). "Diel variations in carbon metabolism by green nonsulfur-like bacteria in alkaline siliceous hot spring microbial mats from Yellowstone National Park". Appl Environ Microbiol 71 (7): 3978–86. doi:10.1128/AEM.71.7.3978-3986.2005. PMID 16000812. PMC 1168979. http://aem.asm.org/cgi/pmidlookup?view=long&pmid=16000812.  
  47. ^ Tichi M, Tabita F (2001). "Interactive control of Rhodobacter capsulatus redox-balancing systems during phototrophic metabolism". J Bacteriol 183 (21): 6344–54. doi:10.1128/JB.183.21.6344-6354.2001. PMID 11591679. PMC 100130. http://jb.asm.org/cgi/pmidlookup?view=long&pmid=11591679.  
  48. ^ Allen J, Williams J (1998). "Photosynthetic reaction centers". FEBS Lett 438 (1–2): 5–9. doi:10.1016/S0014-5793(98)01245-9. PMID 9821949.  
  49. ^ Munekage Y, Hashimoto M, Miyake C, Tomizawa K, Endo T, Tasaka M, Shikanai T (2004). "Cyclic electron flow around photosystem I is essential for photosynthesis". Nature 429 (6991): 579–82. doi:10.1038/nature02598. PMID 15175756.  
  50. ^ Miziorko H, Lorimer G (1983). "Ribulose-1,5-bisphosphate carboxylase-oxygenase". Annu Rev Biochem 52: 507–35. doi:10.1146/annurev.bi.52.070183.002451. PMID 6351728.  
  51. ^ Dodd A, Borland A, Haslam R, Griffiths H, Maxwell K (2002). "Crassulacean acid metabolism: plastic, fantastic". J Exp Bot 53 (369): 569–80. doi:10.1093/jexbot/53.369.569. PMID 11886877. http://jxb.oxfordjournals.org/cgi/content/full/53/369/569.  
  52. ^ Hügler M, Wirsen C, Fuchs G, Taylor C, Sievert S (May 2005). "Evidence for autotrophic CO2 fixation via the reductive tricarboxylic acid cycle by members of the epsilon subdivision of proteobacteria". J Bacteriol 187 (9): 3020–7. doi:10.1128/JB.187.9.3020-3027.2005. PMID 15838028. PMC 1082812. http://jb.asm.org/cgi/pmidlookup?view=long&pmid=15838028.  
  53. ^ Strauss G, Fuchs G (1993). "Enzymes of a novel autotrophic CO2 fixation pathway in the phototrophic bacterium Chloroflexus aurantiacus, the 3-hydroxypropionate cycle". Eur J Biochem 215 (3): 633–43. doi:10.1111/j.1432-1033.1993.tb18074.x. PMID 8354269.  
  54. ^ Wood H (1991). "Life with CO or CO2 and H2 as a source of carbon and energy". FASEB J 5 (2): 156–63. PMID 1900793. http://www.fasebj.org/cgi/reprint/5/2/156.  
  55. ^ Shively J, van Keulen G, Meijer W (1998). "Something from almost nothing: carbon dioxide fixation in chemoautotrophs". Annu Rev Microbiol 52: 191–230. doi:10.1146/annurev.micro.52.1.191. PMID 9891798.  
  56. ^ Boiteux A, Hess B (1981). "Design of glycolysis". Philos Trans R Soc Lond B Biol Sci 293 (1063): 5–22. doi:10.1098/rstb.1981.0056. PMID 6115423.  
  57. ^ Pilkis S, el-Maghrabi M, Claus T (1990). "Fructose-2,6-bisphosphate in control of hepatic gluconeogenesis. From metabolites to molecular genetics". Diabetes Care 13 (6): 582–99. doi:10.2337/diacare.13.6.582. PMID 2162755.  
  58. ^ a b Ensign S (2006). "Revisiting the glyoxylate cycle: alternate pathways for microbial acetate assimilation". Mol Microbiol 61 (2): 274–6. doi:10.1111/j.1365-2958.2006.05247.x. PMID 16856935.  
  59. ^ Finn P, Dice J (2006). "Proteolytic and lipolytic responses to starvation". Nutrition 22 (7–8): 830–44. doi:10.1016/j.nut.2006.04.008. PMID 16815497.  
  60. ^ a b Kornberg H, Krebs H (1957). "Synthesis of cell constituents from C2-units by a modified tricarboxylic acid cycle". Nature 179 (4568): 988–91. doi:10.1038/179988a0. PMID 13430766.  
  61. ^ Rademacher T, Parekh R, Dwek R (1988). "Glycobiology". Annu Rev Biochem 57: 785–838. doi:10.1146/annurev.bi.57.070188.004033. PMID 3052290.  
  62. ^ Opdenakker G, Rudd P, Ponting C, Dwek R (1993). "Concepts and principles of glycobiology". FASEB J 7 (14): 1330–7. PMID 8224606. http://www.fasebj.org/cgi/reprint/7/14/1330.  
  63. ^ McConville M, Menon A (2000). "Recent developments in the cell biology and biochemistry of glycosylphosphatidylinositol lipids (review)". Mol Membr Biol 17 (1): 1–16. doi:10.1080/096876800294443. PMID 10824734.  
  64. ^ Chirala S, Wakil S (2004). "Structure and function of animal fatty acid synthase". Lipids 39 (11): 1045–53. doi:10.1007/s11745-004-1329-9. PMID 15726818.  
  65. ^ White S, Zheng J, Zhang Y (2005). "The structural biology of type II fatty acid biosynthesis". Annu Rev Biochem 74: 791–831. doi:10.1146/annurev.biochem.74.082803.133524. PMID 15952903.  
  66. ^ Ohlrogge J, Jaworski J (1997). "Regulation of fatty acid synthesis". Annu Rev Plant Physiol Plant Mol Biol 48: 109–136. doi:10.1146/annurev.arplant.48.1.109. PMID 15012259.  
  67. ^ Dubey V, Bhalla R, Luthra R (2003). "An overview of the non-mevalonate pathway for terpenoid biosynthesis in plants" (PDF). J Biosci 28 (5): 637–46. doi:10.1007/BF02703339. PMID 14517367. http://www.ias.ac.in/jbiosci/sep2003/637.pdf.  
  68. ^ a b Kuzuyama T, Seto H (2003). "Diversity of the biosynthesis of the isoprene units". Nat Prod Rep 20 (2): 171–83. doi:10.1039/b109860h. PMID 12735695.  
  69. ^ Grochowski L, Xu H, White R (May 2006). "Methanocaldococcus jannaschii uses a modified mevalonate pathway for biosynthesis of isopentenyl diphosphate". J Bacteriol 188 (9): 3192–8. doi:10.1128/JB.188.9.3192-3198.2006. PMID 16621811. PMC 1447442. http://jb.asm.org/cgi/pmidlookup?view=long&pmid=16621811.  
  70. ^ Lichtenthaler H (1999). "The 1-Ddeoxy-D-xylulose-5-phosphate pathway of isoprenoid biosynthesis in plants". Annu Rev Plant Physiol Plant Mol Biol 50: 47–65. doi:10.1146/annurev.arplant.50.1.47. PMID 15012203.  
  71. ^ a b Schroepfer G (1981). "Sterol biosynthesis". Annu Rev Biochem 50: 585–621. doi:10.1146/annurev.bi.50.070181.003101. PMID 7023367.  
  72. ^ Lees N, Skaggs B, Kirsch D, Bard M (1995). "Cloning of the late genes in the ergosterol biosynthetic pathway of Saccharomyces cerevisiae—a review". Lipids 30 (3): 221–6. doi:10.1007/BF02537824. PMID 7791529.  
  73. ^ Guyton, Arthur C.; John E. Hall (2006). Textbook of Medical Physiology. Philadelphia: Elsevier. pp. 855–6. ISBN 0-7216-0240-1.  
  74. ^ Ibba M, Söll D (2001). "The renaissance of aminoacyl-tRNA synthesis". EMBO Rep 2 (5): 382–7. PMID 11375928. http://www.molcells.org/home/journal/include/downloadPdf.asp?articleuid={A158E3B4-2423-4806-9A30-4B93CDA76DA0}.  
  75. ^ Lengyel P, Söll D (1969). "Mechanism of protein biosynthesis". Bacteriol Rev 33 (2): 264–301. PMID 4896351.  
  76. ^ a b Rudolph F (1994). "The biochemistry and physiology of nucleotides". J Nutr 124 (1 Suppl): 124S–127S. PMID 8283301.   Zrenner R, Stitt M, Sonnewald U, Boldt R (2006). "Pyrimidine and purine biosynthesis and degradation in plants". Annu Rev Plant Biol 57: 805–36. doi:10.1146/annurev.arplant.57.032905.105421. PMID 16669783.  
  77. ^ Stasolla C, Katahira R, Thorpe T, Ashihara H (2003). "Purine and pyrimidine nucleotide metabolism in higher plants". J Plant Physiol 160 (11): 1271–95. doi:10.1078/0176-1617-01169. PMID 14658380.  
  78. ^ Smith J (1995). "Enzymes of nucleotide synthesis". Curr Opin Struct Biol 5 (6): 752–7. doi:10.1016/0959-440X(95)80007-7. PMID 8749362.  
  79. ^ Testa B, Krämer S (2006). "The biochemistry of drug metabolism—an introduction: part 1. Principles and overview". Chem Biodivers 3 (10): 1053–101. doi:10.1002/cbdv.200690111. PMID 17193224.  
  80. ^ Danielson P (2002). "The cytochrome P450 superfamily: biochemistry, evolution and drug metabolism in humans". Curr Drug Metab 3 (6): 561–97. doi:10.2174/1389200023337054. PMID 12369887.  
  81. ^ King C, Rios G, Green M, Tephly T (2000). "UDP-glucuronosyltransferases". Curr Drug Metab 1 (2): 143–61. doi:10.2174/1389200003339171. PMID 11465080.  
  82. ^ Sheehan D, Meade G, Foley V, Dowd C (November 2001). "Structure, function and evolution of glutathione transferases: implications for classification of non-mammalian members of an ancient enzyme superfamily". Biochem J 360 (Pt 1): 1–16. doi:10.1042/0264-6021:3600001. PMID 11695986. PMC 1222196. http://www.biochemj.org/bj/360/0001/bj3600001.htm.  
  83. ^ Galvão T, Mohn W, de Lorenzo V (2005). "Exploring the microbial biodegradation and biotransformation gene pool". Trends Biotechnol 23 (10): 497–506. doi:10.1016/j.tibtech.2005.08.002. PMID 16125262.  
  84. ^ Janssen D, Dinkla I, Poelarends G, Terpstra P (2005). "Bacterial degradation of xenobiotic compounds: evolution and distribution of novel enzyme activities". Environ Microbiol 7 (12): 1868–82. doi:10.1111/j.1462-2920.2005.00966.x. PMID 16309386.  
  85. ^ Davies K (1995). "Oxidative stress: the paradox of aerobic life". Biochem Soc Symp 61: 1–31. PMID 8660387.  
  86. ^ Tu B, Weissman J (2004). "Oxidative protein folding in eukaryotes: mechanisms and consequences". J Cell Biol 164 (3): 341–6. doi:10.1083/jcb.200311055. PMID 14757749. PMC 2172237. http://www.jcb.org/cgi/content/full/164/3/341.  
  87. ^ Sies H (1997). "Oxidative stress: oxidants and antioxidants" (PDF). Exp Physiol 82 (2): 291–5. PMID 9129943. http://ep.physoc.org/cgi/reprint/82/2/291.pdf.  
  88. ^ Vertuani S, Angusti A, Manfredini S (2004). "The antioxidants and pro-antioxidants network: an overview". Curr Pharm Des 10 (14): 1677–94. doi:10.2174/1381612043384655. PMID 15134565.  
  89. ^ von Stockar U, Liu J (1999). "Does microbial life always feed on negative entropy? Thermodynamic analysis of microbial growth". Biochim Biophys Acta 1412 (3): 191–211. doi:10.1016/S0005-2728(99)00065-1. PMID 10482783.  
  90. ^ Demirel Y, Sandler S (2002). "Thermodynamics and bioenergetics". Biophys Chem 97 (2–3): 87–111. doi:10.1016/S0301-4622(02)00069-8. PMID 12050002.  
  91. ^ Albert R (2005). "Scale-free networks in cell biology". J Cell Sci 118 (Pt 21): 4947–57. doi:10.1242/jcs.02714. PMID 16254242. http://jcs.biologists.org/cgi/content/full/118/21/4947.  
  92. ^ Brand M (1997). "Regulation analysis of energy metabolism". J Exp Biol 200 (Pt 2): 193–202. PMID 9050227. http://jeb.biologists.org/cgi/reprint/200/2/193.  
  93. ^ Soyer O, Salathé M, Bonhoeffer S (2006). "Signal transduction networks: topology, response and biochemical processes". J Theor Biol 238 (2): 416–25. doi:10.1016/j.jtbi.2005.05.030. PMID 16045939.  
  94. ^ a b Salter M, Knowles R, Pogson C (1994). "Metabolic control". Essays Biochem 28: 1–12. PMID 7925313.  
  95. ^ Westerhoff H, Groen A, Wanders R (1984). "Modern theories of metabolic control and their applications (review)". Biosci Rep 4 (1): 1–22. doi:10.1007/BF01120819. PMID 6365197.  
  96. ^ Fell D, Thomas S (1995). "Physiological control of metabolic flux: the requirement for multisite modulation". Biochem J 311 (Pt 1): 35–9. PMID 7575476.  
  97. ^ Hendrickson W (2005). "Transduction of biochemical signals across cell membranes". Q Rev Biophys 38 (4): 321–30. doi:10.1017/S0033583506004136. PMID 16600054.  
  98. ^ Cohen P (2000). "The regulation of protein function by multisite phosphorylation—a 25 year update". Trends Biochem Sci 25 (12): 596–601. doi:10.1016/S0968-0004(00)01712-6. PMID 11116185.  
  99. ^ Lienhard G, Slot J, James D, Mueckler M (1992). "How cells absorb glucose". Sci Am 266 (1): 86–91. PMID 1734513.  
  100. ^ Roach P (2002). "Glycogen and its metabolism". Curr Mol Med 2 (2): 101–20. doi:10.2174/1566524024605761. PMID 11949930.  
  101. ^ Newgard C, Brady M, O'Doherty R, Saltiel A (2000). "Organizing glucose disposal: emerging roles of the glycogen targeting subunits of protein phosphatase-1" (PDF). Diabetes 49 (12): 1967–77. doi:10.2337/diabetes.49.12.1967. PMID 11117996. http://diabetes.diabetesjournals.org/cgi/reprint/49/12/1967.pdf.  
  102. ^ Romano A, Conway T (1996). "Evolution of carbohydrate metabolic pathways". Res Microbiol 147 (6–7): 448–55. doi:10.1016/0923-2508(96)83998-2. PMID 9084754.  
  103. ^ Koch A (1998). "How did bacteria come to be?". Adv Microb Physiol 40: 353–99. doi:10.1016/S0065-2911(08)60135-6. PMID 9889982.  
  104. ^ Ouzounis C, Kyrpides N (1996). "The emergence of major cellular processes in evolution". FEBS Lett 390 (2): 119–23. doi:10.1016/0014-5793(96)00631-X. PMID 8706840.  
  105. ^ Caetano-Anolles G, Kim HS, Mittenthal JE (2007). "The origin of modern metabolic networks inferred from phylogenomic analysis of protein architecture". Proc Natl Acad Sci USA 104 (22): 9358–63. doi:10.1073/pnas.0701214104. PMID 17517598.  
  106. ^ Schmidt S, Sunyaev S, Bork P, Dandekar T (2003). "Metabolites: a helping hand for pathway evolution?". Trends Biochem Sci 28 (6): 336–41. doi:10.1016/S0968-0004(03)00114-2. PMID 12826406.  
  107. ^ Light S, Kraulis P (2004). "Network analysis of metabolic enzyme evolution in Escherichia coli". BMC Bioinformatics 5: 15. doi:10.1186/1471-2105-5-15. PMID 15113413.   Alves R, Chaleil R, Sternberg M (2002). "Evolution of enzymes in metabolism: a network perspective". J Mol Biol 320 (4): 751–70. doi:10.1016/S0022-2836(02)00546-6. PMID 12095253.  
  108. ^ Kim HS, Mittenthal JE, Caetano-Anolles G (2006). "MANET: tracing evolution of protein architecture in metabolic networks". BMC Bioinformatics 19 (7): 351. doi:10.1186/1471-2105-7-351. PMID 16854231.  
  109. ^ Teichmann SA, Rison SC, Thornton JM, Riley M, Gough J, Chothia C (2001). "Small-molecule metabolsim: an enzyme mosaic". Trends Biotechnol 19 (12): 482–6. doi:10.1016/S0167-7799(01)01813-3. PMID 11711174.  
  110. ^ Spirin V, Gelfand M, Mironov A, Mirny L (June 2006). "A metabolic network in the evolutionary context: multiscale structure and modularity". Proc Natl Acad Sci USA 103 (23): 8774–9. doi:10.1073/pnas.0510258103. PMID 16731630. PMC 1482654. http://www.pnas.org/cgi/pmidlookup?view=long&pmid=16731630.  
  111. ^ Lawrence J (2005). "Common themes in the genome strategies of pathogens". Curr Opin Genet Dev 15 (6): 584–8. doi:10.1016/j.gde.2005.09.007. PMID 16188434.   Wernegreen J (2005). "For better or worse: genomic consequences of intracellular mutualism and parasitism". Curr Opin Genet Dev 15 (6): 572–83. doi:10.1016/j.gde.2005.09.013. PMID 16230003.  
  112. ^ Pál C, Papp B, Lercher M, Csermely P, Oliver S, Hurst L (2006). "Chance and necessity in the evolution of minimal metabolic networks". Nature 440 (7084): 667–70. doi:10.1038/nature04568. PMID 16572170.  
  113. ^ Rennie M (1999). "An introduction to the use of tracers in nutrition and metabolism". Proc Nutr Soc 58 (4): 935–44. doi:10.1017/S002966519900124X. PMID 10817161.  
  114. ^ Phair R (1997). "Development of kinetic models in the nonlinear world of molecular cell biology". Metabolism 46 (12): 1489–95. doi:10.1016/S0026-0495(97)90154-2. PMID 9439549.  
  115. ^ Sterck L, Rombauts S, Vandepoele K, Rouzé P, Van de Peer Y (2007). "How many genes are there in plants (... and why are they there)?". Curr Opin Plant Biol 10 (2): 199–203. doi:10.1016/j.pbi.2007.01.004. PMID 17289424.  
  116. ^ Borodina I, Nielsen J (2005). "From genomes to in silico cells via metabolic networks". Curr Opin Biotechnol 16 (3): 350–5. doi:10.1016/j.copbio.2005.04.008. PMID 15961036.  
  117. ^ Gianchandani E, Brautigan D, Papin J (2006). "Systems analyses characterize integrated functions of biochemical networks". Trends Biochem Sci 31 (5): 284–91. doi:10.1016/j.tibs.2006.03.007. PMID 16616498.  
  118. ^ Duarte NC, Becker SA, Jamshidi N, et al. (February 2007). "Global reconstruction of the human metabolic network based on genomic and bibliomic data". Proc. Natl. Acad. Sci. U.S.A. 104 (6): 1777–82. doi:10.1073/pnas.0610772104. PMID 17267599. PMC 1794290. http://www.pnas.org/cgi/pmidlookup?view=long&pmid=17267599.  
  119. ^ Goh KI, Cusick ME, Valle D, Childs B, Vidal M, Barabási AL (May 2007). "The human disease network". Proc. Natl. Acad. Sci. U.S.A. 104 (21): 8685–90. doi:10.1073/pnas.0701361104. PMID 17502601.  
  120. ^ Lee DS, Park J, Kay KA, Christakis NA, Oltvai ZN, Barabási AL (July 2008). "The implications of human metabolic network topology for disease comorbidity". Proc. Natl. Acad. Sci. U.S.A. 105 (29): 9880–9885. doi:10.1073/pnas.0802208105. PMID 18599447. PMC 2481357. http://www.pnas.org/lookup/pmid?view=long&pmid=18599447.  
  121. ^ Thykaer J, Nielsen J (2003). "Metabolic engineering of beta-lactam production". Metab Eng 5 (1): 56–69. doi:10.1016/S1096-7176(03)00003-X. PMID 12749845.   González-Pajuelo M, Meynial-Salles I, Mendes F, Andrade J, Vasconcelos I, Soucaille P (2005). "Metabolic engineering of Clostridium acetobutylicum for the industrial production of 1,3-propanediol from glycerol". Metab Eng 7 (5–6): 329–36. doi:10.1016/j.ymben.2005.06.001. PMID 16095939.   Krämer M, Bongaerts J, Bovenberg R, Kremer S, Müller U, Orf S, Wubbolts M, Raeven L (2003). "Metabolic engineering for microbial production of shikimic acid". Metab Eng 5 (4): 277–83. doi:10.1016/j.ymben.2003.09.001. PMID 14642355.  
  122. ^ Koffas M, Roberge C, Lee K, Stephanopoulos G (1999). "Metabolic engineering". Annu Rev Biomed Eng 1: 535–57. doi:10.1146/annurev.bioeng.1.1.535. PMID 11701499.  
  123. ^ "Metabolism". The Online Etymology Dictionary. http://www.etymonline.com/index.php?term=metabolism. Retrieved 2007-02-20.  
  124. ^ Dr. Abu Shadi Al-Roubi (1982), "Ibn Al-Nafis as a philosopher", Symposium on Ibn al Nafis, Second International Conference on Islamic Medicine: Islamic Medical Organization, Kuwait (cf. Ibnul-Nafees As a Philosopher, Encyclopedia of Islamic World [1]).
  125. ^ Eknoyan G (1999). "Santorio Sanctorius (1561–1636) - founding father of metabolic balance studies". Am J Nephrol 19 (2): 226–33. doi:10.1159/000013455. PMID 10213823.  
  126. ^ Williams, H. S. (1904) A History of Science: in Five Volumes. Volume IV: Modern Development of the Chemical and Biological Sciences Harper and Brothers (New York) Retrieved on 2007-03-26
  127. ^ Dubos J. (1951). "Louis Pasteur: Free Lance of Science, Gollancz. Quoted in Manchester K. L. (1995) Louis Pasteur (1822 – 1895)—chance and the prepared mind". Trends Biotechnol 13 (12): 511–515. doi:10.1016/S0167-7799(00)89014-9. PMID 8595136.  
  128. ^ Kinne-Saffran E, Kinne R (1999). "Vitalism and synthesis of urea. From Friedrich Wöhler to Hans A. Krebs". Am J Nephrol 19 (2): 290–4. doi:10.1159/000013463. PMID 10213830.  
  129. ^ Eduard Buchner's 1907 Nobel lecture at http://nobelprize.org Accessed 2007-03-20
  130. ^ Kornberg H (2000). "Krebs and his trinity of cycles". Nat Rev Mol Cell Biol 1 (3): 225–8. doi:10.1038/35043073. PMID 11252898.  
  131. ^ Krebs HA, Henseleit K (1932). "Untersuchungen über die Harnstoffbildung im tierkorper". Z. Physiol. Chem. 210: 33–66.  
    Krebs H, Johnson W (April 1937). "Metabolism of ketonic acids in animal tissues". Biochem J 31 (4): 645–60. PMID 16746382.  

Further reading

Introductory
  • Rose, S. and Mileusnic, R., The Chemistry of Life. (Penguin Press Science, 1999), ISBN 0-14027-273-9
  • Schneider, E. D. and Sagan, D., Into the Cool: Energy Flow, Thermodynamics, and Life. (University Of Chicago Press, 2005), ISBN 0-22673-936-8
  • Lane, N., Oxygen: The Molecule that Made the World. (Oxford University Press, USA, 2004), ISBN 0-19860-783-0
Advanced
  • Price, N. and Stevens, L., Fundamentals of Enzymology: Cell and Molecular Biology of Catalytic Proteins. (Oxford University Press, 1999), ISBN 0-19850-229-X
  • Berg, J. Tymoczko, J. and Stryer, L., Biochemistry. (W. H. Freeman and Company, 2002), ISBN 0-71674-955-6
  • Cox, M. and Nelson, D. L., Lehninger Principles of Biochemistry. (Palgrave Macmillan, 2004), ISBN 0-71674-339-6
  • Brock, T. D. Madigan, M. T. Martinko, J. and Parker J., Brock's Biology of Microorganisms. (Benjamin Cummings, 2002), ISBN 0-13066-271-2
  • Da Silva, J.J.R.F. and Williams, R. J. P., The Biological Chemistry of the Elements: The Inorganic Chemistry of Life. (Clarendon Press, 1991), ISBN 0-19855-598-9
  • Nicholls, D. G. and Ferguson, S. J., Bioenergetics. (Academic Press Inc., 2002), ISBN 0-12518-121-3

External links

.

1911 encyclopedia

Up to date as of January 14, 2010

From LoveToKnow 1911

METABOLISM (from Gr. /hera130Xii, change), the biological term for the process of chemical change in a living cell (see Physiology) .


Simple English

Metabolism is the system of chemical activities by which a living thing gets power (energy) from other things such as food. This depends, for example, on how often someone eats. If they are hungry their metabolism slows down dramatically. Metabolism uses energy to fuel all organs involved in digestion and respiration and so on. The new amount of energy used to carry out these life processes is called the BMR-rate or "basal metabolic rate". The bigger someone is, the lower their metabolism rate would become. This is due to a lower volume to surface area ratio.

Other pages

krc:Метаболизм



Citable sentences

Up to date as of December 10, 2010

Here are sentences from other pages on Metabolism, which are similar to those in the above article.








Got something to say? Make a comment.
Your name
Your email address
Message