From Wikipedia, the free encyclopedia
.^ Enzyme catalysis is a biological subsidiary of both of these catalytic processes occurring in living organisms.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
It deals with the
structures and functions of cellular components such as
proteins,
carbohydrates,
lipids,
nucleic acids and other
biomolecules.
.^ The S N 2 mechanism will have a large negative entropy of activation since the activated complex is formed by combining two molecules.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
^ The number of times that a molecule of catalyst cycles through the loop per unit time is called the turnover number of the catalyst.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ We can think of the activated complex as an unstable “molecule,” with many of the properties of a molecule, except that it decomposes spontaneously either to reactants or to products.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
Each class of polymeric biomolecule has a different set of subunit types.
[1] .^ An enzyme is a large protein molecule (typically of molar mass 20,000 g/mol or more) with a structure capable of catalyzing a specific reaction or series of reactions.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
.^ Many chemical reactions in living systems are catalyzed by enzymes.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
^ These are regions on the surface of the enzyme where the local structures and chemical properties will selectively bind a specific substrate so articular chemical transformations of it can be carried out.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
^ The concepts of energy and entropy are important in understanding chemical reactions.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
The biochemistry of
cell metabolism and the
endocrine system has been extensively described.
.^ It also reverses the transport of neurotransmitters from within the cells plasma membrane into the extracellular space [10] .- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
History
.^ By studying many chemical reactions in this way, we discover that this result, known as Hess' Law , is general.- Energetics of Chemical Reactions 2 February 2010 14:014 UTC cnx.org [Source type: Academic]
^ BIOL 112 General Biology II BIOL 112 General Biology II Presents a comprehensive base in biology for majors and non-science majors and is the second of a two-semester sequence.- Trinity Academic Catalog - Biochemistry 10 February 2010 12:18 UTC www.trinitydc.edu [Source type: Academic]
^ MATH 255A Calculus for the Life Sciences I (3) MATH 255B Calculus for the Life Sciences II (3) PHYS 100A/L General Physics I and Lab (3/1) PHYS 100B/L General Physics II and Lab (3/1) CHEM 101/L General Chemistry I and Lab (4/1) CHEM 102/L General Chemistry II and Lab (4/1) 2.- Chemistry and Biochemistry 10 February 2010 12:18 UTC www.csun.edu [Source type: Academic]
.^ If we could watch every collision, we might see that only 1 collision in 10, or in 100, had both molecules properly oriented for reaction.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
^ Each molecule of water hydrogen bonds with other water molecules, aligning so as to produce a positive, negative repeating pattern.- Chemical Reactions And Energy, Electron Pairs, Covalent Bonds, Acids, Bases, Salts 2 February 2010 14:014 UTC ezinearticles.com [Source type: FILTERED WITH BAYES]
- Chemical Reactions and Energy; Formation of ions; Electron pairs, covalent bonds; Acids, Bases, Salts 2 February 2010 14:014 UTC 001yourtranslationservice.com [Source type: FILTERED WITH BAYES]
^ The only variables are the distances from the central hydrogen atom to the other two, r 1 and r 2 ; r 1 being the distance between the first two atoms, while r 2 is the distance between the second and third atoms.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
Then, in 1828,
Friedrich Wöhler published a paper on the synthesis of
urea, proving that
organic compounds can be created artificially.
[2][3]
.^ This simplified rate law, which may be integrated or subjected to finite difference analysis, is called a pseudo-first order rate law.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
Eduard Buchner contributed the first demonstration of a complex biochemical process outside of a cell in 1896:
alcoholic fermentation in cell extracts of yeast. Although the term “biochemistry” seems to have been first used in 1882, it is generally accepted that the formal coinage of biochemistry occurred in 1903 by
Carl Neuberg, a German
chemist. Previously, this area would have been referred to as
physiological chemistry. Since then, biochemistry has advanced, especially since the mid-20th century, with the development of new techniques such as
chromatography,
X-ray diffraction,
dual polarisation interferometry,
NMR spectroscopy,
radioisotopic labeling,
electron microscopy and
molecular dynamics simulations.
.^ Similarly, many other possible orientations of these two molecules are unsuitable for transfer of an oxygen atom from N to C, so will not be effective.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
Another significant historic event in biochemistry is the discovery of the
gene and its role in the transfer of information in the cell.
.^ Molecular rearrangements (often called isomerization reactions) frequently follow first order rate laws.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
In the 1950s,
James D. Watson,
Francis Crick,
Rosalind Franklin, and
Maurice Wilkins were instrumental in solving DNA structure and suggesting its relationship with genetic transfer of information.
.^ The process is referred to as Ziegler-Natta catalysis after its two coinventors, who jointly received the Nobel Prize in Chemistry in 1963.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ One of today's common methods, called the 'temperature-jump' or 'T-jump' method, was developed in the 1950s by German physicist Manfred Eigen , who later shared the 1967 Nobel Prize in Chemistry for his work.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
In 1988,
Colin Pitchfork was the first person convicted of murder with
DNA evidence, which led to growth of
forensic science. More recently,
Andrew Z. Fire and
Craig C. Mello received the 2006 Nobel Prize for discovering the role of
RNA interference (
RNAi), in the silencing of gene expression
.^ There are three main categories of reversible inhibition: competitive, uncompetitive, and mixed.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
^ There are three types of elementary process, named for their molecularity --the number of reactant molecules that they involve.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
Plant biochemistry involves the study of the biochemistry of
autotrophic organisms such as
photosynthesis and other plant specific
biochemical processes. General biochemistry encompasses both plant and animal biochemistry. Human/medical/medicinal biochemistry focuses on the biochemistry of humans and medical illnesses.
[citation needed]
Monomers and Polymers
Main articles:
Monomer and
PolymerMonomers and
polymers are a structural basis in which the four main
macromolecules (
carbohydrates,
lipids,
proteins, and
nucleic acids), or
biopolymers, of biochemistry are based on.
Monomers are smaller micromolecules that are put together to make macromolecules.
Polymers are those macromolecules that are created when monomers are synthesized together.
.^ There are three types of elementary process, named for their molecularity --the number of reactant molecules that they involve.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ The concept of molecularity is appropriate only in the context of an elementary process, and indicates the number of reactant molecules involved in (undergoing collision) in the elementary step.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ They consist of very long molecules called polypeptides, which are formed by stringing amino acids together.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
Carbohydrates
Carbohydrates have monomers called
monosaccharides. Some of these
monosaccharides include
glucose (C
6H
12O
6),
fructose (C
6H
12O
6), and
deoxyribose (C
5H
10O
4).
.^ A mixture of hydrogen and oxygen gas can be kept for years without reacting to produce a significant amount of water.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
^ The experimental rate law demands that there be two N atoms and four O atoms in the rds reactants; however, only one N and three O atoms are involved in the rds of mechanism 3.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ Cl and O atoms are bonded at the start, and the two ClO molecules are too far apart to exert any influence on one another.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
Lipids
A triglyceride with a glycerol molecule on the left and three fatty acids coming off it.
.^ We may think of it as a "molecule" in which chemical bonds are in flux, some being broken and others being made.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
.^ There is one activated complex for each step, for a total of three.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ Some chemical processes are simple one-step reactions involving one, two, or occasionally three molecules.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
^ There are three main categories of reversible inhibition: competitive, uncompetitive, and mixed.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
.^ For 13 years after this rate law was discovered, no one could account for it.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
^ Naming Some Inorganic Compounds • Acidic Salts are made from ternary acids that retain one or more of their acidic hydrogen atoms.- CHAPTER 04 Some Types of Chemical Reactions 2 February 2010 14:014 UTC www.scribd.com [Source type: Reference]
^ The bond angle in H 2 S is 92° in contrast to the 105° in (a)]]In the original thioacetamide molecule, the central carbon atom is bound to carbon and to nitrogen by σ bonds , and by a σ and a π double bond to sulfur (Figure 22-1a).- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
.^ However, the values are not too much different, so either may be used as an estimate of the rate of reaction at the 20 second mark.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
in
Parenteral infusions or else as drug carrier components (e.g. in a
Liposome or
Transfersome).
Proteins
Main articles:
Proteins and
Amino Acids
The general structure of an α-amino acid, with the
amino group on the left and the
carboxyl group on the right.
Proteins are macro
biopolymers, and have monomers of
amino acids.
.^ They consist of very long molecules called polypeptides, which are formed by stringing amino acids together.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
.^ Although a catalyst and an intermediate share the property of not appearing in the overall equation, they are different types of things.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
.^ They consist of very long molecules called polypeptides, which are formed by stringing amino acids together.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ A bond cannot form between atoms in separate molecules unless they are near each other during collision.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ Although they are traditionally unreactive, CH bonds can form by coordination using a catalyst.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
Nucleic Acids
.^ For these reasons and others, chemists have developed other methods for determining rate laws from data, which make use of all of the data collected.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ They consist of very long molecules called polypeptides, which are formed by stringing amino acids together.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ Before leaving this matter, we make one more very important point.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
The most common nucleic acids are
deoxyribonucleic acid and
ribonucleic acid. Their monomers are called
nucleotides. The most common nucleotides are called
adenine,
cytosine,
guanine,
thymine, and
uracil. Adenine binds with thymine and uracil, thymine only binds with adenine. Cytosine and guanine can only bind with each other.
Carbohydrates
Main article:
Carbohydrate.^ Study of protein structure and function enzyme mechanisms, biological membranes, carbohydrate metabolism, ATP generation and lipid metabolism.- Chemistry and Biochemistry 10 February 2010 12:18 UTC www.csun.edu [Source type: Academic]
^ This table does not include any reference to rearrangement, due to the fact that such reactions are found in all functional classes, and are highly dependent on the structure of the reactant.- Chemical Reactivity 2 February 2010 14:014 UTC www.cem.msu.edu [Source type: Reference]
^ Topics may include membrane structure, phospholipid biosynthesis and transport, organelle biogenesis, membrane protein and phospholipid sorting, membrane transport, vesicular transport, membrane coat protein structure and function, and membrane-dependent signal transduction.- Graduate Program Brochure - Chemistry and Biochemistry 10 February 2010 12:18 UTC chemistry.csulb.edu [Source type: Academic]
Sugars are carbohydrates, but not all carbohydrates are sugars. There are more carbohydrates on Earth than any other known type of biomolecule; they are used to store energy and genetic information, as well as play important roles in cell to cell interactions and communications.
Monosaccharides
.^ The general formula for carbohydrates is (CH 2 O) n .
^ Compounds containing hydrogen and carbon.- TE Chemical Reactions - CK12 - Flexbooks 2 February 2010 14:014 UTC authors.ck12.org [Source type: Academic]
^ Carbohydrates contain only the elements carbon, hydrogen and oxygen.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
.^ We make one final and very important point about the entries in the table under the reaction in the example just completed: only the entries in the D P line of the table are governed by the reaction stoichiometry.- Chapter 12: Principles of ChemicalEquilibrium 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ Example: Glucose , fructose, and galactose are monosaccharides; their structural formula is C 6 H 12 O 6 .
^ The most common and important monosaccharide is glucose , which is a six-carbon or hexose sugar, so has the formula C 6 H 12 O 6 .- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
So is
fructose, the sugar that gives
fruits their sweet taste. Some carbohydrates (especially after
condensation to oligo- and polysaccharides) contain less carbon relative to H and O, which still are present in 2:1 (H:O) ratio. Monosaccharides can be grouped into
aldoses (having an
aldehyde group at the end of the chain, e. g. glucose) and
ketoses (having a
keto group in their chain; e. g. fructose).
.^ The connection between the equilibrium constant for a reaction and the rate constants of the elementary steps by which it occurs is an important one.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
.^ Binding of A and B to C causes shifts in electron density that may facilitate bond breaking within A and/or B and bond formation between A and B or fragments of them.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ A bond cannot form between atoms in separate molecules unless they are near each other during collision.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ These elements form a class of compounds in which the transition metal is bonded to a number of ions or molecules via covalent bonds.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
This leads to saturated five-membered (in furanoses) or six-membered (in pyranoses)
heterocyclic rings containing one O as heteroatom.
Disaccharides
Sucrose: ordinary table sugar and probably the most familiar carbohydrate.
.^ Naming Some Inorganic Compounds • Acidic Salts are made from ternary acids that retain one or more of their acidic hydrogen atoms.- CHAPTER 04 Some Types of Chemical Reactions 2 February 2010 14:014 UTC www.scribd.com [Source type: Reference]
^ Old system used the prefix “bi” to denote the hydrogen atom.- CHAPTER 04 Some Types of Chemical Reactions 2 February 2010 14:014 UTC www.scribd.com [Source type: Reference]
^ Metathesis reactions remove ions from solution in two ways: form predominantly unionized molecules like H2O form an insoluble solid .- CHAPTER 04 Some Types of Chemical Reactions 2 February 2010 14:014 UTC www.scribd.com [Source type: Reference]
.^ At pH 7.0, most of the acetic acid molecules have donated their protons to OH - to form water.
^ Water can even act as an acid with another molecule of water, which acts as a base, to form H 3 O + and OH - , a strong acid and base respectively.
.^ Under certain conditions, ethylene molecules can be made to join together end-to-end to form very long chain-like molecules of polyethylene , so called because it consists of many (poly) ethylenes.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ They consist of very long molecules called polypeptides, which are formed by stringing amino acids together.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ Reaction requires that bonds within reactants be broken and that new bonds form between atoms in the colliding molecules.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
.^ The reaction involves the formation of a molecule of water (H 2 O): .- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ The reverse reaction also can occur; a molecule of H 2 S can collide with one of acetamide and produce water and thioacetamide.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
^ Disaccharides are formed when two monosaccharides are joined together by a glycosidic bond .- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
The most well-known disaccharide is
sucrose, ordinary
sugar (in scientific contexts, called
table sugar or
cane sugar to differentiate it from other sugars).
.^ Sucrose (or cane sugar) is glucose 1-2 fructose.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ The atoms in the molecules of basic gases such as oxygen, nitrogen and hydrogen are all joined together with covalent bonds.- Chemical Reactions And Energy, Electron Pairs, Covalent Bonds, Acids, Bases, Salts 2 February 2010 14:014 UTC ezinearticles.com [Source type: FILTERED WITH BAYES]
^ This shows two glucose molecules joining together to form the disaccharide maltose .- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
.^ Lactose (or milk sugar) is galactose 1-4 glucose.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ This shows two glucose molecules joining together to form the disaccharide maltose .- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
As most humans age, the production of
lactase, the enzyme that hydrolyzes lactose back into glucose and galactose, typically decreases. This results in
lactase deficiency, also called
lactose intolerance.
.^ Sucrose is called a non-reducing sugar because it does not reduce copper sulphate, so there is no direct test for sucrose.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ Non-reducing Sugars (Benedict's test).- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
.^ In the first step of this process, the OH- group forms a bond to the carbon atom that is attached to Cl-, forming an intermediate in which this carbon atom is attached to 5 other groups.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ In the S N 2 mechanism, Y attacks the carbon atom in R-X and forms a weak bond.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
.^ The uncatalyzed reaction is thought to occur in a single elementary step, in which bromide ion attacks the hydroxyl carbon atom of ethanol while the hydroxide group simultaneously departs: .- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ In the organism, however, they take place briskly and specifically (i.e., only the desired products are formed), thanks to nature's catalytic molecules, the enzymes.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ R represents a carbon-containing group of atoms that may be simple (for example, CH 3 ) or more complex (for example, (CH 3 ) 3 C-).- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
This prevents opening of the chain to the aldehyde or keto form and renders the modified residue non-reducing.
.^ Lactose (or milk sugar) is galactose 1-4 glucose.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ Starch and glycogen contain a-glucose, in which the hydroxyl group on carbon 1 sticks down from the ring, while cellulose contains b-glucose , in which the hydroxyl group on carbon 1 sticks up.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ In the first step of this process, the OH- group forms a bond to the carbon atom that is attached to Cl-, forming an intermediate in which this carbon atom is attached to 5 other groups.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
.^ Because reaction involves the breaking of the F-F bond and formation of a bond between N and F, the structure shown in Figure 15-14a is a reasonable arrangement of atoms in the activated complex.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
Oligosaccharides and polysaccharides
When a few (around three to six) monosaccharides are joined together, it is called an
oligosaccharide (
oligo- meaning "few").
.^ Use paints, petroleum products, ammonia, bleach, and other products that give off fumes only in a well-ventilated area.- Chemical Burn Or Reaction | LIVESTRONG.COM 2 February 2010 14:014 UTC www.livestrong.com [Source type: General]
^ Second, some classes of organic compounds have distinctly acidic properties, and some other classes behave as bases, so we need to identify these aspects of their chemistry.- Chemical Reactivity 2 February 2010 14:014 UTC www.cem.msu.edu [Source type: Reference]
^ Due to these facts, some of these oscillating reactions are used as chemical clocks.- Oscillating reactions and chemical waves by G. Dupuis and N. Berland - Lyc�e Faidherbe 2 February 2010 14:014 UTC www.faidherbe.org [Source type: Academic]
.^ Polysaccharides are long chains of many monosaccharides joined together by glycosidic bonds.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ Disaccharides are formed when two monosaccharides are joined together by a glycosidic bond .- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ The figure makes it clear that N 2 O 4 is the result of the joining together of two 1-bond NO 2 fragments, as discussed in Chapter 3 .- Chapter 12: Principles of ChemicalEquilibrium 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
.^ In a protein the polypeptide chain may be hundreds of amino acids long.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ Under certain conditions, ethylene molecules can be made to join together end-to-end to form very long chain-like molecules of polyethylene , so called because it consists of many (poly) ethylenes.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ They consist of very long molecules called polypeptides, which are formed by stringing amino acids together.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
Two of the most common polysaccharides are
cellulose and
glycogen, both consisting of repeating
glucose monomers.
- Cellulose is made by plants and is an important structural component of their cell walls. Humans can neither manufacture nor digest it.
- Glycogen, on the other hand, is an animal carbohydrate; humans and other animals use it as a form of energy storage.
Use of carbohydrates as an energy source
- See also carbohydrate metabolism
Glucose is the major energy source in most life forms. For instance, polysaccharides are broken down into their monomers (
glycogen phosphorylase removes glucose residues from glycogen). Disaccharides like lactose or
sucrose are cleaved into their two component monosaccharides.
Glycolysis (anaerobic)
.^ Sustained muscle action depends on the continuous supply of energy produced by glucose combustion in the mitochondria of cells.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ The connection between the equilibrium constant for a reaction and the rate constants of the elementary steps by which it occurs is an important one.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ The total of their concentrations is then very slowly reduced as B converts to C. Figure 15-22b shows the course of reaction over a longer time.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
g. in humans) or to
ethanol plus carbon dioxide (e. g. in
yeast).
.^ The oxidation catalyst, on the other hand, helps convert the carbon monoxide into carbon dioxide in the presence of oxygen: .- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
Aerobic
In
aerobic cells with sufficient oxygen, like most human cells, the pyruvate is further metabolized.
.^ This is why there are only carbon dioxide and water as products.- Chemical Reactions - CK12 - Flexbooks 2 February 2010 14:014 UTC authors.ck12.org [Source type: Reference]
^ Use paints, petroleum products, ammonia, bleach, and other products that give off fumes only in a well-ventilated area.- Chemical Burn Or Reaction | LIVESTRONG.COM 2 February 2010 14:014 UTC www.livestrong.com [Source type: General]
^ For the completely general chemical reaction in 15-1-7, proceeding from left to right from reactants, A and B, to products, D and F, the rate of reaction can be represented using any one of the expressions in 15-1-8: .- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
The two molecules acetyl-CoA (from one molecule of glucose) then enter the
citric acid cycle, producing two more molecules of ATP, six more
NADH molecules and two reduced (ubi)quinones (via
FADH2 as enzyme-bound cofactor), and releasing the remaining carbon atoms as carbon dioxide.
.^ This implies that 1 molecule of enzyme and 1 molecule of substrate must collide and interact in order to form products.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ Similarly, many other possible orientations of these two molecules are unsuitable for transfer of an oxygen atom from N to C, so will not be effective.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ The complex, Fe(CN) 5 X 3- , where X is a variety of neutral molecules, is particularly convenient to study because the CN- ligands are very difficult to replace.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
.^ The oxygen atoms then react rapidly with hydrogen molecules, colliding with them, forming water, and regenerating the catalyst.- CHEMICAL REACTION, 2 February 2010 14:014 UTC www.history.com [Source type: FILTERED WITH BAYES]
^ The reaction occurs with each magnesium atom giving up two electrons and being oxidized and each oxygen atom accepting two electrons and being reduced.- chemical reaction :: Classifying chemical reactions -- Britannica Online Encyclopedia 2 February 2010 14:014 UTC www.britannica.com [Source type: Reference]
.^ This is why there are only carbon dioxide and water as products.- Chemical Reactions - CK12 - Flexbooks 2 February 2010 14:014 UTC authors.ck12.org [Source type: Reference]
^ A hydrocarbon contains carbon and hydrogen atoms (and sometimes oxygen is within the molecule), and they combine with oxygen in chemical reactions to form carbon dioxide and water.- Balancing Equations, Chemical Reaction Types & Redox Equations 2 February 2010 14:014 UTC www.avon-chemistry.com [Source type: FILTERED WITH BAYES]
^ Pee Pals will gross out your kids' friends while proving that carbon dioxide gas bubbles can make heavy objects float.- Howstuffworks "Science Projects for Kids: Chemical Reactions" 2 February 2010 14:014 UTC home.howstuffworks.com [Source type: General]
.^ This method is dependent on the equivalence of heat and work as transfers of energy, and on the law of conservation of energy.- Energetics of Chemical Reactions 2 February 2010 14:014 UTC cnx.org [Source type: Academic]
^ First, energy is released in a chemical reaction due to the formation of strong bonds.- Energetics of Chemical Reactions 2 February 2010 14:014 UTC cnx.org [Source type: Academic]
^ This is a statement of the conservation of energy: the energy in the reactant state does not depend upon the processes which produced that state.- Energetics of Chemical Reactions 2 February 2010 14:014 UTC cnx.org [Source type: Academic]
.^ This shows two glucose molecules joining together to form the disaccharide maltose .- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ The number of times that a molecule of catalyst cycles through the loop per unit time is called the turnover number of the catalyst.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ Total Units in the Major: 57 General Education Units: 36 Additional Units: 27 Total Units Required for the Degree: 120 Chemistry Subject Matter Program for the Single Subject Credential .- Chemistry and Biochemistry 10 February 2010 12:18 UTC www.csun.edu [Source type: Academic]
.^ As in the fermentation of glucose, this is a more complex reaction than it appears here because it is a biochemical reaction.- CHEMTUTOR REACTIONS 2 February 2010 14:014 UTC www.chemtutor.com [Source type: FILTERED WITH BAYES]
^ When Q < 1 (reactants are present in greater relative amounts than products), the equation tells us that D G R < D G R o ; in other words, that reaction is more spontaneous than under standard conditions.- Chapter 12: Principles of ChemicalEquilibrium 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ As a result, when the atom is split, the amount of energy released is large.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
Gluconeogenesis
In
vertebrates, vigorously contracting
skeletal muscles (during weightlifting or sprinting, for example) do not receive enough oxygen to meet the energy demand, and so they shift to
anaerobic metabolism, converting glucose to lactate. The
liver regenerates the glucose, using a process called
gluconeogenesis.
.^ A termolecular process requires the simultaneous collision of three reactant molecules.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ An alternative to pressure or volume measurements is to use gas chromatography to monitor the amounts of gaseous reactants and products as a function of time.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ As such, 4.184J must also be the amount of energy added to the water molecules when they are heated by 1°C rather than stirred.- Energetics of Chemical Reactions 2 February 2010 14:014 UTC cnx.org [Source type: Academic]
.^ Sustained muscle action depends on the continuous supply of energy produced by glucose combustion in the mitochondria of cells.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ All of these will be observed in Lab Experiment 3 in which pure copper foil will be converted through a series of chemical reactions to other substances and ultimately back to copper.
^ Image if you tried to separate the reactions into two beaker, one containing Zn(s) and the other Cu 2+ .
The combined pathways of glycolysis during exercise, lactate's crossing via the bloodstream to the liver, subsequent gluconeogenesis and release of glucose into the bloodstream is called the
Cori cycle.
[citation needed]Proteins
A schematic of
hemoglobin. The red and blue ribbons represent the protein
globin; the green structures are the
heme groups.
.^ Fibrous proteins look like ropes and tend to have structural roles such as collagen (bone), keratin (hair), tubulin (cytoskeleton) and actin (muscle).- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ An enzyme is a large protein molecule (typically of molar mass 20,000 g/mol or more) with a structure capable of catalyzing a specific reaction or series of reactions.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
.^ Actin , one of the proteins found in muscles, consists of many globular subunits arranged in a double helix to form long filaments.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ A few proteins have both structures: the muscle protein myosin has a long fibrous tail and a globular head, which acts as an enzyme.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ Fibrous proteins look like ropes and tend to have structural roles such as collagen (bone), keratin (hair), tubulin (cytoskeleton) and actin (muscle).- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
.^ These are regions on the surface of the enzyme where the local structures and chemical properties will selectively bind a specific substrate so articular chemical transformations of it can be carried out.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
^ We must also know how the molecules approach one another and with what energies and with what orientations they interact.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
^ The coefficients indicate how many molecules of each substance is involved in the reaction and may be changed in order to balance the equation.- Chemical Reactions - CK12 - Flexbooks 2 February 2010 14:014 UTC authors.ck12.org [Source type: Reference]
Antibodies are an example of proteins that attach to one specific type of molecule. In fact, the
enzyme-linked immunosorbent assay (ELISA), which uses antibodies, is currently one of the most sensitive tests modern medicine uses to detect various biomolecules.
.^ Nature has chosen transition metals to serve as the centerpieces for many of its catalysts, the enzymes, most probably for these same reasons.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
.^ The reactant molecule on which the enzyme works is called the substrate .- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ The reactant molecule that is affected by the catalyst is called the substrate .- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ The integer, x, is called the order of the reaction in reactant A ; y is the order in B .- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
.^ The equation above indicates that the rate of reaction is slower if the activation energy is large.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
^ What is the activation energy for the reaction?- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ It is able to do this by providing an alternative mechanism or pathway for the reaction, with a lower activation energy.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
.^ They speed up, or catalyze, chemical reactions.- Howstuffworks "Science Projects for Kids: Chemical Reactions" 2 February 2010 14:014 UTC home.howstuffworks.com [Source type: General]
^ We will define a catalyst as a substance that speeds up a reaction without itself being consumed or chemically changed in the overall reaction process.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ Further, once the spreadsheet is set up for a particular reaction, it can be used for any specified initial conditions.- Chapter 12: Principles of ChemicalEquilibrium 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
.^ The control of enzyme activity and concentration.- Chemistry/Biochemistry 10 February 2010 12:18 UTC www.fullerton.edu [Source type: Academic]
^ In the medical field, enzyme inhibitors are used to bond to enzymes and decrease their activity.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
.^ In a protein the polypeptide chain may be hundreds of amino acids long.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ Proteins are made of amino acids .- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ The tertiary structure is held together by bonds between the R groups of the amino acids in the protein, and so depends on what the sequence of amino acids is.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
.^ There is a central carbon atom (called the "alpha carbon"), with four different chemical groups attached to it: .- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ The tertiary structure is held together by bonds between the R groups of the amino acids in the protein, and so depends on what the sequence of amino acids is.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ The uncatalyzed reaction is thought to occur in a single elementary step, in which bromide ion attacks the hydroxyl carbon atom of ethanol while the hydroxide group simultaneously departs: .- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
.^ Under these conditions, 15-9-4 simplifies to .- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ In a polypeptide there is always one end with a free amino (NH 3 ) group, called the N-terminus , and one end with a free carboxyl (CO 2 ) group, called the C-terminus .- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ These acids and salts will have one less O atom than the “ic” acid.- CHAPTER 04 Some Types of Chemical Reactions 2 February 2010 14:014 UTC www.scribd.com [Source type: Reference]
.^ The only variables are the distances from the central hydrogen atom to the other two, r 1 and r 2 ; r 1 being the distance between the first two atoms, while r 2 is the distance between the second and third atoms.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
.^ You do not need to learn these, but it is interesting to see the different structures, and you should be familiar with the amino acid names.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ Since each R group is slightly different, each amino acid has different properties, and this in turn means that proteins can have a wide range of properties.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ There are 20 different R groups, and so 20 different amino acids.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
.^ There are 3-letter and 1-letter abbreviations for each amino acid.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ There are 20 different R groups, and so 20 different amino acids.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ The Twenty Amino Acid R-Groups .- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
Some of these have functions by themselves or in a modified form; for instance, glutamate functions as an important
neurotransmitter.
Generic amino acids (1) in neutral form, (2) as they exist physiologically, and (3) joined together as a dipeptide.
.^ Amino acids are joined together by peptide bonds .- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ When two amino acids join together a dipeptide is formed.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ Disaccharides are formed when two monosaccharides are joined together by a glycosidic bond .- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
.^ Because this bond is between carbon 1 of one molecule and carbon 4 of the other molecule it is called a 1-4 glycosidic bond.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ Amino acids are joined together by peptide bonds .- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ Concentrated sulphuric acid and water: its a known rule that one should always add sulphuric acid to water and not water to sulphuric acid.- Top 10 Amazing Chemical Reactions - Listverse 2 February 2010 14:014 UTC listverse.com [Source type: General]
.^ They consist of very long molecules called polypeptides, which are formed by stringing amino acids together.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
Longer stretches merit the title
proteins. As an example, the important blood
serum protein
albumin contains 585 amino acid residues.
.^ To help to understand protein structure, it is broken down into four levels: .- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ These four structures are not real stages in the formation of a protein, but are simply a convenient classification that scientists invented to help them to understand proteins.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ Haemoglobin , the oxygen-carrying protein in red blood cells, consists of four globular subunits arranged in a tetrahedral (pyramid) structure.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
.^ Proteins are made of amino acids .- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ So the secondary structure is due to backbone interactions and is thus largely independent of primary sequence, while tertiary structure is due to side chain interactions and thus depends on the amino acid sequence.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ Finding the primary structure of a protein is called protein sequencing , and the first protein to be sequenced was the protein hormone insulin, by the Cambridge biochemist Fredrick Sanger, for which work he got the Nobel prize in 1958.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
.^ They consist of very long molecules called polypeptides, which are formed by stringing amino acids together.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
.^ The final three-dimensional shape of a protein can be classified as globular or fibrous .- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ The tertiary structure is held together by bonds between the R groups of the amino acids in the protein, and so depends on what the sequence of amino acids is.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ Polypeptides are just a string of amino acids, but they fold up to form the complex and well-defined three-dimensional structure of working proteins.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
.^ The tertiary structure is held together by bonds between the R groups of the amino acids in the protein, and so depends on what the sequence of amino acids is.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ The sequence of amino acids in a polypeptide chain is determined by the sequence of the genetic code in DNA. Protein synthesis it studied in detail in module 2.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ So the secondary structure is due to backbone interactions and is thus largely independent of primary sequence, while tertiary structure is due to side chain interactions and thus depends on the amino acid sequence.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
In fact, a single change can change the entire structure. The alpha chain of hemoglobin contains 146 amino acid residues; substitution of the
glutamate residue at position 6 with a
valine residue changes the behavior of hemoglobin so much that it results in
sickle-cell disease. Finally
quaternary structure is concerned with the structure of a protein with multiple peptide subunits, like hemoglobin with its four subunits.
.^ In a "test tube" you would see a single material coming apart into more than one new material.- Balancing Equations, Chemical Reaction Types & Redox Equations 2 February 2010 14:014 UTC www.avon-chemistry.com [Source type: FILTERED WITH BAYES]
^ The form of a chemical equation involves writing the formulas of the reactants (the substances that are mixed together) on the left, using '+' when more than one substance is involved and the formula(s) of the product(s) on the right.- A chemical equation is a symbolic representation of all of the substances involved in a chemical reaction. 2 February 2010 14:014 UTC intro.chem.okstate.edu [Source type: Academic]
^ Very often one of the elementary processes occurs much more slowly than do the others and limits the rate at which the overall reaction occurs.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
.^ Proteins are made of amino acids .- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ To help to understand protein structure, it is broken down into four levels: .- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ The tertiary structure is held together by bonds between the R groups of the amino acids in the protein, and so depends on what the sequence of amino acids is.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
.^ The figure makes it clear that N 2 O 4 is the result of the joining together of two 1-bond NO 2 fragments, as discussed in Chapter 3 .- Chapter 12: Principles of ChemicalEquilibrium 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
.^ Unfortunately, high temperature makes the exothermic reaction less favored, so very high pressure is used to favor products.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ For these reasons and others, chemists have developed other methods for determining rate laws from data, which make use of all of the data collected.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ This is just the sequence of amino acids in the polypeptide chain, so is not really a structure at all.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
Humans and other mammals, however, can only synthesize half of them. They cannot synthesize
isoleucine,
leucine,
lysine,
methionine,
phenylalanine,
threonine,
tryptophan, and
valine.
.^ You do not need to learn these, but it is interesting to see the different structures, and you should be familiar with the amino acid names.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ Since each R group is slightly different, each amino acid has different properties, and this in turn means that proteins can have a wide range of properties.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
Mammals do possess the enzymes to synthesize
alanine,
asparagine,
aspartate,
cysteine,
glutamate,
glutamine,
glycine,
proline,
serine, and
tyrosine, the nonessential amino acids.
.^ Polypeptides are just a string of amino acids, but they fold up to form the complex and well-defined three-dimensional structure of working proteins.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
^ The atomic product of each of these steps is a reactant for the other step, and they both produce HBr.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
^ Amino acids are so-called because they have both amino groups and acid groups, which have opposite charges.- BiologyMad A-Level Biology 10 February 2010 12:18 UTC www.biologymad.com [Source type: Academic]
If the amino group is removed from an amino acid, it leaves behind a carbon skeleton called an α-
keto acid.
.^ They consist of very long molecules called polypeptides, which are formed by stringing amino acids together.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ The decarboxylation of a b -keto acid catalyzed by a decarboxylation enzyme can be measured by the rate of CO 2 formation.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
.^ It has been shown via many research studies over many years that (15-10-6) occurs by two different pathways, depending on the nature of the carbon-containing group R. .- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ In the first step of this process, the OH- group forms a bond to the carbon atom that is attached to Cl-, forming an intermediate in which this carbon atom is attached to 5 other groups.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
.^ They consist of very long molecules called polypeptides, which are formed by stringing amino acids together.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
A similar process is used to break down proteins. It is first hydrolyzed into its component amino acids. Free
ammonia (NH
3), existing as the
ammonium ion (NH
4+) in blood, is toxic to life forms. A suitable method for excreting it must therefore exist. Different strategies have evolved in different animals, depending on the animals' needs.
Unicellular organisms, of course, simply release the ammonia into the environment. Similarly,
bony fish can release the ammonia into the water where it is quickly diluted. In general, mammals convert the ammonia into urea, via the
urea cycle.
Lipids
The term lipid comprises a diverse range of
molecules and to some extent is a catchall for relatively water-insoluble or
nonpolar compounds of biological origin, including
waxes,
fatty acids, fatty-acid derived
phospholipids,
sphingolipids,
glycolipids and
terpenoids (e.g.
retinoids and
steroids).
.^ We may think of it as a "molecule" in which chemical bonds are in flux, some being broken and others being made.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
Some are
aromatic, while others are not. Some are flexible, while others are rigid.
Most lipids have some
polar character in addition to being largely nonpolar. Generally, the bulk of their structure is nonpolar or
hydrophobic ("water-fearing"), meaning that it does not interact well with polar solvents like water. Another part of their structure is polar or
hydrophilic ("water-loving") and will tend to associate with polar solvents like water. This makes them
amphiphilic molecules (having both hydrophobic and hydrophilic portions).
.^ This is because the hydroxyl hydrogen atom on the alcohol is so small and so exposed that it can be attacked by a nucleophilic reagent such as water, where as the analogous --- CH 3 group in the ether blocks the approach of water.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
In the case of phospholipids, the polar groups are considerably larger and more polar, as described below.
.^ Chemical reactions are part of our daily lives.- Top 10 Amazing Chemical Reactions - Listverse 2 February 2010 14:014 UTC listverse.com [Source type: General]
Most
oils and
milk products that we use for cooking and eating like
butter,
cheese,
ghee etc, are composed of
fats.
Vegetable oils are rich in various
polyunsaturated fatty acids (PUFA).
.^ This intermediate chemical undergoes a reduction reaction with a third chemical, and transforms one of the original reactants back to its original state as well as changing the intermediate into the final product.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
^ Never store household products in food or drink containers.- Chemical Burn Or Reaction | LIVESTRONG.COM 2 February 2010 14:014 UTC www.livestrong.com [Source type: General]
Nucleic acids
Main article:
Nucleic acid.^ For this reaction to occur and be efficient, atoms with high molecular weight, such as Plutonium and Uranium , must be used because their Binding Energy is low.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
^ The course covers biochemistry of nucleic acids in living systems at the molecular level.- Chemistry/Biochemistry 10 February 2010 12:18 UTC www.fullerton.edu [Source type: Academic]
The most common nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (
RNA). Nucleic acids are found in all living cells and viruses.
.^ Dimerization reactions , in which two molecules unite to form a larger molecule, obey simple second-order kinetics.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ They consist of very long molecules called polypeptides, which are formed by stringing amino acids together.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ In the organism, however, they take place briskly and specifically (i.e., only the desired products are formed), thanks to nature's catalytic molecules, the enzymes.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
Nucleic acid, so called because of its prevalence in cellular
nuclei, is the generic name of the family of
biopolymers. The monomers are called
nucleotides, and each consists of three components: a nitrogenous heterocyclic
base (either a
purine or a
pyrimidine), a
pentose sugar, and a
phosphate group.
.^ There are actually three different types of single replacement reactions; 1) the single element is a metal and replaces the metal of the compound in the second reactant, 2) the single element is a metal and replaces the hydrogen of the compound in the second reactant which is always an acid, and 3) the single element is a non-metal and replaces the non-metal in the compound.- Chemical Reactions - CK12 - Flexbooks 2 February 2010 14:014 UTC authors.ck12.org [Source type: Reference]
DNA or deoxyribonucleic acid contains 2-
deoxyriboses). Also, the nitrogenous bases possible in the two nucleic acids are different:
adenine,
cytosine, and
guanine occur in both RNA and DNA, while
thymine occurs only in DNA and
uracil occurs in RNA.
Relationship to other "molecular-scale" biological sciences
Schematic relationship between biochemistry, genetics and molecular biology
.^ Several researchers have developed these ideas.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
^ Lee's group at the Lawrence Berkeley Laboratory is also using molecular beams to research photochemical processes .- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
^ As more research is performed using crossed-molecular beam experiments, the ability to control the products of chemical reactions is becoming a reality.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
There has never been a hard-line between these disciplines in terms of content and technique. Today the terms
molecular biology and
biochemistry are nearly interchangeable. The following figure is a schematic that depicts one possible view of the relationship between the fields:
- Biochemistry is the study of the chemical substances and vital processes occurring in living organisms.^ The first order rate law may be rearranged to put the concentration terms on one side and time on the other side of the equals sign, as in 15-3-7 .
- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ We will define a catalyst as a substance that speeds up a reaction without itself being consumed or chemically changed in the overall reaction process.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ Very often one of the elementary processes occurs much more slowly than do the others and limits the rate at which the overall reaction occurs.- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
Biochemists focus heavily on the role, function, and structure of biomolecules. .
- Genetics is the study of the effect of genetic differences on organisms.^ Mechanistic studies are difficult for several reasons, one of which is that the process is heterogeneous ; that is, the catalyst (TiCl 3 ) and substrate (ethylene) are in different phases.
- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ M -1 s -1 at o C. Other examples of dimerization processes are the formation of a Cl 2 molecule from two Cl atoms and the formation of one molecule of C 4 H 8 from two molecules of C 2 H 4 .- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
^ Enzyme catalysis is a biological subsidiary of both of these catalytic processes occurring in living organisms.- Chemical Principles/Rates and Mechanisms of Chemical Reactions - Wikibooks, collection of open-content textbooks 2 February 2010 14:014 UTC en.wikibooks.org [Source type: Academic]
Often this can be inferred by the absence of a normal component (e.g. one gene). The study of "mutants" – organisms which lack one or more functional components with respect to the so-called "wild type" or normal phenotype. Genetic interactions (epistasis) can often confound simple interpretations of such "knock-out" studies.
- Molecular biology is the study of molecular underpinnings of the process of replication, transcription and translation of the genetic material. .^ Description: Prerequisite: Chemistry 423A. Survey of biochemistry designed for Biochemistry majors; structural chemistry and function of biomolecules, central metabolism; replication and expression of the genetic material.
- Chemistry/Biochemistry 10 February 2010 12:18 UTC www.fullerton.edu [Source type: Academic]
^ BACHELOR OF SCIENCE IN BIOCHEMISTRY The Bachelor of Science degree in Biochemistry is recommended for students planning to go directly into professional biochemistry careers and for students planning to attend graduate school in biochemistry or molecular biology.- Chemistry/Biochemistry 10 February 2010 12:18 UTC www.fullerton.edu [Source type: Academic]
^ Biology Biochemistry Cellular Biology Genetics Genomics Genomics Microbiology Bacteriology Molecular Biology Health Sciences Biochemistry ( More ) ( Collapse ) .- Academia.edu | People | People who have Biochemistry as a research interest (63) 10 February 2010 12:18 UTC www.academia.edu [Source type: Academic]
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- Chemical Biology seeks to develop new tools based on small molecules that allow minimal perturbation of biological systems while providing detailed information about their function.^ The mechanism in all of its detail is seldom observable; it must be deduced from experiment, must be consistent with all known experimental facts about the reaction, and is subject to change if in conflict with a new experimental fact.
- Chapter 15: Principles of Chemical Dynamics 2 February 2010 14:014 UTC www.wpi.edu [Source type: Academic]
Further, chemical biology employs biological systems to create non-natural hybrids between biomolecules and synthetic devices (for example emptied viral capsids that can deliver gene therapy or drug molecules).
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