From Wikipedia, the free encyclopedia
Biophysics (also biological
physics or biophysical chemistry) is an
interdisciplinary science that employs and develops theories and
methods of the physical sciences for the
investigation of biological
systems [1].
Studies included under the branches of biophysics span all levels of biological
organization, from the molecular scale to whole organisms and
ecosystems. Biophysical research shares significant overlap with biochemistry, nanotechnology,
bioengineering, agrophysics and systems biology.
Molecular biophysics typically addresses biological questions
that are similar to those in biochemistry and molecular
biology, but the questions are approached quantitatively.
Scientists in this field conduct research concerned with
understanding the interactions between the various systems of a
cell, including the interactions between DNA, RNA and protein
biosynthesis, as well as how these interactions are regulated. A
great variety of techniques are used to answer these questions.
Fluorescent imaging techniques, as well as
electron microscopy, x-ray
crystallography, NMR spectroscopy and atomic force microscopy (AFM) are often
used to visualize structures of biological significance. Conformational change in
structure can be measured using techniques such as dual
polarisation interferometry and circular dichroism. Direct
manipulation of molecules using optical tweezers or AFM can also be
used to monitor biological events where forces and distances are at
the nanoscale. Molecular biophysicists often consider complex
biological events as systems of interacting units which can be
understood through statistical mechanics, thermodynamics
and chemical
kinetics. By drawing knowledge and experimental techniques from
a wide variety of disciplines, biophysicists are often able to
directly observe, model or even manipulate the structures and
interactions of individual molecules or complexes of molecules.
In addition to traditional (i.e. molecular and cellular)
biophysical topics like structural biology or enzyme kinetics,
modern biophysics encompasses an extraordinarily broad range of
research. It is becoming increasingly common for biophysicists to
apply the models and experimental techniques derived from physics, as well as mathematics and statistics, to larger
systems such as tissues, organs, populations and ecosystems.
Focus as a
subfield
Biophysics often does not have university-level departments of
its own, but has presence as groups across departments within the
fields of molecular biology, biochemistry, chemistry, computer
science, mathematics, medicine, pharmacology, physiology, physics, and neuroscience. What follows is a list of
examples of how each department applies its efforts toward the
study of biophysics. This list is hardly all inclusive. Nor does
each subject of study belong exclusively to any particular
department. Each academic institution makes its own rules and there
is much overlap between departments.
- Biology and molecular
biology - Almost all forms of biophysics efforts are included
in some biology department somewhere. To include some: gene regulation, single protein dynamics, bioenergetics, patch clamping, biomechanics.
- Structural biology -
Ångstrom-resolution structures of proteins, nucleic acids, lipids,
carbohydrates, and complexes thereof.
- Biochemistry
and chemistry -
biomolecular structure, siRNA, nucleic acid structure,
structure-activity relationships.
- Computer
science - Neural networks, biomolecular and drug
databases.
- Computational chemistry - molecular
dynamics simulation, molecular docking, quantum
chemistry
- Bioinformatics - sequence
alignment, structural alignment, protein structure
prediction
- Mathematics -
graph/network theory, population modeling, dynamical systems, phylogenetics.
- Medicine and neuroscience -
tackling neural networks experimentally (brain slicing) as well as
theoretically (computer models), membrane permitivity, gene
therapy, understanding tumors.
- Pharmacology
and physiology -
channel biology, biomolecular interactions, cellular membranes,
polyketides.
- Physics - biomolecular
free energy, stochastic
processes, covering dynamics.
- Quantum Biophysics involves quantum information processing of
coherent states, entanglement between coherent protons and
transcriptase components and replication of decohered isomers to
yield time-dependent base substitutions. These studies imply
applicatons in quantum computing.
- Agronomy Agriculture
Many biophysical techniques are
unique to this field. Research efforts in biophysics are often
initiated by scientists who were traditional physicists, chemists,
and biologists by training.
Topics in biophysics
and related fields
Famous
biophysicists
- Luigi
Galvani, discoverer of bioelectricity
- Hermann von Helmholtz, first to
measure the velocity of nerve impulses;
studied hearing and vision
- Alan Hodgkin & Andrew Huxley, mathematical
theory of how ion fluxes produce
nerve
impulses
- Georg von Békésy, research on the
human ear
- Bernard Katz,
discovered how synapses
work
- G. N.
Ramachandran Computation of relative stability of Protein Structure, famous for Ramachandran
plot.
- Hermann J. Muller, discovered
that X-rays cause mutations
- George Palade Nobel Laureate in physiology
or medicine for protein secretion and cell ultra-structure from
electron microscopy studies
- Linus
Pauling & Robert Corey, co-discoverers of the alpha helix and beta sheet structures in
proteins
- J. D. Bernal, X-ray
crystallography of plant viruses and proteins
- Rosalind
Franklin, Maurice Wilkins, James D. Watson
and Francis
Crick, pioneers of DNA crystallography
and co-discoverers of the structure of DNA. Francis Crick later participated in the Crick, Brenner et al.
experiment which established the basis for understanding the genetic code
- Max Perutz &
John Kendrew,
pioneers of protein crystallography
- Sir John Randall, X-ray and neutron
diffraction of proteins and DNA
- Ronald Burge, X-ray diffraction of nerve myelin, bacterial cell
walls and membranes
- Allan Cormack & Godfrey
Hounsfield, development of computer assisted
tomography
- Kurt
Wüthrich Nobel Laureate in physiology or medicine for 2D-FT NMR
of protein structure in solution[2]
- Paul
Lauterbur & Peter Mansfield, development of magnetic resonance
imaging
- Stephen
D. Levene, DNA-protein Interactions, DNA looping, and DNA
topology.
- Seiji Ogawa,
development of functional magnetic resonance imaging
Other notable
biophysicists
- Adolf
Eugen Fick, responsible for Fick's law of diffusion and a method to
determine cardiac
output.
- Howard Berg,
characterized properties of bacterial chemotaxis
- Steven Block,
observed the motions of enzymes such as kinesin and RNA polymerase with optical
tweezers
- Carlos
Bustamante, known for single-molecule biophysics of molecular motors and biological polymer
physics
- Steven Chu, Nobel
laureate who helped develop optical trapping techniques used by
many biophysicists
- Christoph
Cremer, overcoming the conventional limit of resolution that
applies to light based investigations (the Abbe limit) by a range of different methods
- Friedrich Dessauer, research on
radiation, especially X-rays
- Julio Fernandez
- Govindjee, professor emeritus at the University of Illinois, research in
photosynthesis and photosynthetic mechanisms by fluorescence and
NMR methods
- Enrico Gratton research on frequency domain spectroscopy and
correlation spectroscopy on biological and biomedical systems
- Stefan Hell,
developed the principle of STED microscopy
- Richard
Henderson, scientist at the MRC Laboratory of Molecular
Biology, developed the use of cryo-EM to study membrane protein
structures.
- John J. Hopfield, worked on error
correction in transcription and translation (kinetic
proof-reading), and associative memory models (Hopfield net)
- Martin
Karplus, research on molecular dynamical simulations of
biological macromolecules.
- Franklin Offner, professor emeritus at Northwestern University of
professor of biophysics, biomedical engineering and electronics who
developed a modern prototype of the electroencephalograph and electrocardiograph called the
dynograph.
- Nicolas
Rashevsky,[3], former
Editor of the first journal of mathematical and theoretical
biophysics entitled " The Bulletin of Mathematical
Biophysics " (1940—1973) and author of the two-factor model of
neuronal excitation, biotopology and organismic set theory.
- Arieh
Warshel, the development of QM/MM approaches, paving the way
for a quantitative understanding of enzymatic reactions, and
allowing for the first consistent modeling of the catalytic effect
of an enzyme; the introduction of MD simulations in biology; the
introduction of consistent electrostatic calculations in
proteins.
- Robert Rosen,
theoretical biophysicist and mathematical biologist, author of:
metabolic-replication systems, categories of metabolic and genetic
networks, quantum genetics in terms of von Neumann's approach,
non-reductionist complexity theories, dynamical and anticipatory
systems in biology.[4]
- Benoit Roux
- Mikhail Volkenshtein, Revaz Dogonadze
& Zurab Urushadze, authors of the first quantum-mechanical model of enzyme
catalysis, supported a theory that enzyme catalysis use
quantum-mechanical effects such as tunneling.
- John Wikswo,
research on biomagnetism and cardiac electrophysiology
- Douglas
Warrick, specializing in bird flight (hummingbirds and pigeons)
- Ernest
C. Pollard — founder of the Biophysical Society
- Marvin
Makinen, pioneer of the structural basis of enzyme action
- Gopalasamudram Narayana Iyer Ramachandran,
developer of the Ramachandran plot and pioneer of the
collagen triple-helix structure prediction
- Doug Barrick, repeat protein folding
- Naomi Courtemanche, kinetics of leucine rich repeat protein
folding
- Ellen Kloss, salt-dependence of leucine rich repeat protein
folding
- Bertrand Garcia Moreno E., Dielectric Constant of Globular
Protein 'hydrophobic' core
- Ludwig Brand, Time resolved fluorescence anisotropy decay in
Biological systems
- Eduardo Ducla Soares, founder of IBEB (Institute of Biophysics
and Biomedical Engineering)
See also
Notes
References
- Perutz MF (1962). Proteins and
Nucleic Acids: Structure and Function. Amsterdam: Elsevier. ASIN B000TS8P4G.
- Perutz MF (1969). "The
haemoglobin molecule". Proceedings of the Royal Society of
London. Series B 173 (31):
113–40.
PMID 4389425
- Dogonadze RR, Urushadze ZD
(1971). "Semi-Classical Method of Calculation of Rates of Chemical
Reactions Proceeding in Polar Liquids". J Electroanal
Chem 32: 235–245.
- Volkenshtein M.V., Dogonadze R.R., Madumarov A.K., Urushadze
Z.D. and Kharkats Yu.I. Theory of Enzyme Catalysis.-
Molekuliarnaya Biologia (Moscow), 6, 1972,
pp. 431-439 (In Russian, English summary)
- Rodney M. J.
Cotterill (2002). Biophysics : An Introduction.
Wiley. ISBN
978-0471485384.
- Sneppen K, Zocchi G (2005-10-17).
Physics in Molecular Biology (1 ed.). Cambridge University Press.
ISBN
0-521-84419-3.
- Glaser, Roland (2004-11-23).
Biophysics: An Introduction (Corrected ed.). Springer. ISBN
3-540-67088-2.
- Hobbie RK, Roth BJ (2006). Intermediate Physics for
Medicine and Biology (4th ed.). Springer. ISBN
978-0387309422. http://personalwebs.oakland.edu/~roth/hobbie.htm.
- Cooper WG (2009). "Evidence for
transcriptase quantum processing implies entanglement and
decoherence of superposition proton states". BioSystems
97: 73–89.
- Cooper WG (2009). "Necessity of
quantum coherence to account for the spectrum of time-dependent
mutations exhibited by bacteriophage T4". Biochem. Genet.
47: 892.
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