Biophysics

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Biophysics is an interdisciplinary science that applies approaches and methods traditionally used in physics to study biological phenomena.[1][2][3] Biophysics covers all scales of biological organization, from molecular to organismic and populations. Biophysical research shares significant overlap with biochemistry, molecular biology, physical chemistry, physiology, nanotechnology, bioengineering, computational biology, biomechanics and systems biology.

The term biophysics was originally introduced by Karl Pearson in 1892.[4][5] Ambiguously, the term biophysics is also regularly[6][7][8][9][10][11][12][13] used in academia to indicate the study of the physical quantities (e.g. electric current, temperature, stress, entropy) in biological systems, which is, by definition, performed by physiology.[14] Nevertheless, other biological sciences also perform research on the biophysical properties of living organisms including molecular biology,[9] cell biology,[15] biophysics[16] and biochemistry.[17]

Overview[edit]

Molecular biophysics typically addresses biological questions similar to those in biochemistry and molecular biology, seeking to find the physical underpinnings of biomolecular phenomena. 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, atomic force microscopy (AFM) and small-angle scattering (SAS) both with X-rays and neutrons (SAXS/SANS) are often used to visualize structures of biological significance. Protein dynamics can be observed by neutron spin echo spectroscopy. Conformational change in structure can be measured using techniques such as dual polarisation interferometry, circular dichroism, SAXS and SANS. 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 entities which can be understood e.g. 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, from bioelectronics to quantum biology involving both experimental and theoretical tools. 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. Biophysical models are used extensively in the study of electrical conduction in single neurons, as well as neural circuit analysis in both tissue and whole brain.

Medical physics, a branch of biophysics, is any application of physics to medicine or healthcare, ranging from radiology to microscopy and nanomedicine. For example, physicist Richard Feynman theorized about the future of nanomedicine. He wrote about the idea of a medical use for biological machines (see nanomachines). Feynman and Albert Hibbs suggested that certain repair machines might one day be reduced in size to the point that it would be possible to (as Feynman put it) "swallow the doctor". The idea was discussed in Feynman's 1959 essay There's Plenty of Room at the Bottom.[18]

History[edit]

Some of the earlier studies in biophysics were conducted in the 1840s by a group known as the Berlin school of physiologists. Among its members were pioneers such as Hermann von Helmholtz, Ernst Heinrich Weber, Carl F. W. Ludwig, and Johannes Peter Müller.[19] Biophysics might even be seen as dating back to the studies of Luigi Galvani.

The popularity of the field rose when the book What Is Life? by Erwin Schrödinger was published. Since 1957 biophysicists have organized themselves into the Biophysical Society which now has about 9,000 members over the world.[20]

Some authors such as Robert Rosen criticize biophysics on the ground that the biophysical method does not take into account the specificity of biological phenomena[21]

Focus as a subfield[edit]

While some colleges and universities have dedicated departments of biophysics, usually at the graduate level, many do not have university-level biophysics departments, instead having groups in related departments such as biochemistry, cell biology, chemistry, computer science, engineering, mathematics, medicine, molecular biology, neuroscience, pharmacology, physics, and physiology. Depending on the strengths of a department at a university differing emphasis will be given to fields of biophysics. 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.

Many biophysical techniques are unique to this field. Research efforts in biophysics are often initiated by scientists who were biologists, chemists or physicists by training.

See also[edit]

References[edit]

  1. ^ "Biophysics | science". Encyclopedia Britannica. Retrieved 2018-07-26. 
  2. ^ Zhou HX (March 2011). "Q&A: What is biophysics?". BMC Biology. 9: 13. doi:10.1186/1741-7007-9-13. PMC 3055214Freely accessible. PMID 21371342. 
  3. ^ "the definition of biophysics". www.dictionary.com. Retrieved 2018-07-26. 
  4. ^ Pearson, Karl (1892). The Grammar of Science. p. 470. 
  5. ^ Roland Glaser. Biophysics: An Introduction. Springer; 23 April 2012. ISBN 978-3-642-25212-9.
  6. ^ Cooper CE, Walsberg GE, Withers PC (August 2003). "Biophysical properties of the pelt of a diurnal marsupial, the numbat (Myrmecobius fasciatus), and its role in thermoregulation". The Journal of Experimental Biology. 206 (Pt 16): 2771–7. doi:10.1242/jeb.00484. PMID 12847122. 
  7. ^ Kawana M, Sarkar SS, Sutton S, Ruppel KM, Spudich JA (February 2017). "Biophysical properties of human β-cardiac myosin with converter mutations that cause hypertrophic cardiomyopathy". Science Advances. 3 (2): e1601959. Bibcode:2017SciA....3E1959K. doi:10.1126/sciadv.1601959. PMC 5302870Freely accessible. PMID 28246639. 
  8. ^ Trón L, Aszalós A, Balázs M, Mulhern SA, Szöllösi J, Damjanovich S (November 1988). "On the biophysics of transmembrane signalling". Molecular Immunology. 25 (11): 1075–80. PMID 3065628. 
  9. ^ a b Liu Y, Berrido AM, Hua ZC, Tse-Dinh YC, Leng F (November 2017). "Biochemical and biophysical properties of positively supercoiled DNA". Biophysical Chemistry. 230: 68–73. doi:10.1016/j.bpc.2017.08.008. PMC 5773249Freely accessible. PMID 28887044. 
  10. ^ Baris TZ, Crawford DL, Oleksiak MF (January 2016). "Acclimation and acute temperature effects on population differences in oxidative phosphorylation". American Journal of Physiology. Regulatory, Integrative and Comparative Physiology. 310 (2): R185–96. doi:10.1152/ajpregu.00421.2015. PMC 4796645Freely accessible. PMID 26582639. 
  11. ^ Zhou Y, Yang H, Cui J, Lingle CJ (November 2017). "Threading the biophysics of mammalian Slo1 channels onto structures of an invertebrate Slo1 channel". The Journal of General Physiology. 149 (11): 985–1007. doi:10.1085/jgp.201711845. PMC 5677106Freely accessible. PMID 29025867. 
  12. ^ Kolesov G, Wunderlich Z, Laikova ON, Gelfand MS, Mirny LA (August 2007). "How gene order is influenced by the biophysics of transcription regulation". Proceedings of the National Academy of Sciences of the United States of America. 104 (35): 13948–53. Bibcode:2007PNAS..10413948K. doi:10.1073/pnas.0700672104. PMC 1955771Freely accessible. PMID 17709750. 
  13. ^ Sansom MS (1991). "The biophysics of peptide models of ion channels". Progress in Biophysics and Molecular Biology. 55 (3): 139–235. doi:10.1016/0079-6107(91)90004-C. PMID 1715999. 
  14. ^ Zhou Y, Yang H, Cui J, Lingle CJ (November 2017). "Threading the biophysics of mammalian Slo1 channels onto structures of an invertebrate Slo1 channel". The Journal of General Physiology. 149 (11): 985–1007. doi:10.1085/jgp.201711845. PMC 5677106Freely accessible. PMID 29025867. 
  15. ^ Streuli CH (October 2016). "Integrins as architects of cell behavior". Molecular Biology of the Cell. 27 (19): 2885–8. doi:10.1091/mbc.E15-06-0369. PMC 5042575Freely accessible. PMID 27687254. 
  16. ^ Flenner E, Marga F, Neagu A, Kosztin I, Forgacs G (2008). "Relating biophysical properties across scales". Current Topics in Developmental Biology. 81: 461–83. arXiv:0706.3693Freely accessible. doi:10.1016/S0070-2153(07)81016-7. ISBN 9780123742537. PMID 18023738. 
  17. ^ Jusuf S, Loll PJ, Axelsen PH (April 2002). "The Role of Configurational Entropy in Biochemical Cooperativity". Journal of the American Chemical Society. 124 (14): 3490–3491. doi:10.1021/ja017259h. 
  18. ^ Feynman RP (December 1959). "There's Plenty of Room at the Bottom". 
  19. ^ Franceschetti DR (15 May 2012). Applied Science. Salem Press Inc. p. 234. ISBN 978-1-58765-781-8. 
  20. ^ Rosen J, Gothard LQ (2009). Encyclopedia of Physical Science. Infobase Publishing. p. 4 9. ISBN 978-0-8160-7011-4. 
  21. ^ Longo G, Montévil M (2012-01-01). "The Inert vs. the Living State of Matter: Extended Criticality, Time Geometry, Anti-Entropy - An Overview". Frontiers in Physiology. 3: 39. doi:10.3389/fphys.2012.00039. PMC 3286818Freely accessible. PMID 22375127. 

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