Biophysics
Biophysics (also
biological physics) is an
interdisciplinary science that applies the theories and methods of
physical sciences, especially those of
physics, to questions of
biology.
Biophysics research today comprises a number of specific biological studies, which do not share a unique identifying factor, or subject themselves to clear and concise definitions. This is the result of biophysics' relatively recent appearance as a scientific discipline. The studies included under the umbrella of biophysics range from
sequence comparison to
neural networks. In the recent past, biophysics included creating mechanical limbs and nanomachines to regulate biological functions. Nowadays, these are more commonly referred to as belonging to the fields of
bioengineering and
nanotechnology respectively. We may expect these definitions to further refine themselves.
Traditional studies in
biology are conducted using
statistical ensemble experiments, typically using pico- to micro-
molar concentrations of
macromolecules. Because the molecules that comprise living cells are so small, techniques such as
PCR amplification, gel blotting,
fluorescence labeling and
in vivo staining are used so that experimental results are observable with an unaided eye or, at most,
optical magnification. Using these techniques,
biologists attempt to elucidate the complex systems of interactions that give rise to the processes that make life possible. Biophysics typically addresses biological questions similar to those in biology, but the questions are asked at a
molecular (i.e. low
Reynolds number) level. By drawing knowledge and experimental techniques from a wide variety of disciplines (as described below), biophysicists are able to indirectly observe or model the structures and interactions of
individual molecules or complexes of molecules. In addition to things like solving a
protein structure or measuring the
kinetics of
single molecule interactions, biophysics is also understood to encompass research areas that apply models and experimental techniques derived from
physics (e.g.
electromagnetism and
quantum mechanics) to larger systems such as tissues or organs (hence the inclusion of basic
neuroscience as well as more applied techniques such as
fMRI).
Biophysics often does not have university-level departments of its own, but have presence as groups across departments within the fields of
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 mixing between departments.
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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.
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Structural biology - angstrom-resolution structures of proteins, nucleic acids, lipids, carbohydrates, and complexes thereof.
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Biochemistry and
chemistry - biomolecular structure, siRNA, nucleic acid structure, structure-activity relationships.
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Computer science - molecular simulations,
sequence alignment, neural networks, databases.
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Mathematics - graph/network theory, population modeling, dynamical systems,
phylogenetical analysis.
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Medicine and
neuroscience - tackling neural networks experimentally (brain slicing) as well as theoretically (computer models), membrane permitivity, gene therapy, understanding tumors.
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Pharmacology and
physiology - channel biology, biomolecular interactions, cellular membranes, polyketides.
*
Physics - biomolecular free energy, biomolecular structures and dynamics, protein folding, stochastic processes, surface dynamics.
Many
biophysical techniques are unique to this field.Many of the research traditions in biophysics were initiated by scientists who were straight physicists, chemists, and biologists by training.
*
Animal locomotion*
Cellular biophysics*
Channels,
receptors and
transporters
*
Electrophysiology*
Cell membranes
*
Bioenergetics*
Molecular motors*
Muscle and
contractility*
Nucleic acids
*
Photobiophysics and
biophotonics*
Proteins*
Signaling*
Supramolecular assemblies*
Spectroscopy,
imaging, etc.
*
Systems neuroscience*
Neural encoding*
Bionics*
Polysulphur membranes*
Biosensor and
Bioelectronics*
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
*
Hermann J. Muller, discovered that
X-rays cause
mutations
*
Linus Pauling &
Robert Corey, co-discoverers of the
alpha helix and
beta sheet structures in
proteins
*
Fritz-Albert Popp, pioneer of
biophotons work
*
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
genetic code*
Max Perutz &
John Kendrew, pioneers of
protein crystallography*
Allan Cormack &
Godfrey Hounsfield, development of
computer assisted tomography*
Paul Lauterbur &
Peter Mansfield, development of
magnetic resonance imaging*
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
*
Friedrich Dessauer, research on radiation, especially
X-rays
*
Julio Fernandez*
John J. Hopfield, worked on error correction in Transcription and Translation (kinetic proof-reading), and associative memory models (
Hopfield net)
*
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
*
Benoit Roux*
Mikhail Volkenshtein,
Revaz Dogonadze &
Zurab Urushadze, authors of the 1st
Quantum-Mechanical (Physical) Model of Enzyme Catalysis, supported a theory that enzyme catalysis use quantum-mechanical effects such as
tunneling.
*
John P. Wikswo, research on biomagnetism
*
Douglas Warrick, specializing in
bird flight (
hummingbirds and
pigeons)
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Balaji V N, specialized in computational biology
* Perutz M.F. Proteins and Nucleic Acids, Elsevier, Amsterdam, 1962
* PMID 4389425
* Dogonadze R.R. and Urushadze Z.D. Semi-Classical Method of Calculation of Rates of Chemical Reactions Proceeding in Polar Liquids.-
J.Electroanal.Chem., 32, 1971, pp. 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)
*
Important publications in biophysics (biology),
important publications in biophysics (physics)*
Biophysical Society
