Biophysics

Last updated
Kinesin uses protein domain dynamics on nanoscales to walk along a microtubule. Kinesin walking.gif
Kinesin uses protein domain dynamics on nanoscales to walk along a microtubule.

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, developmental biology and systems biology.

Contents

The term biophysics was originally introduced by Karl Pearson in 1892. [4] [5] Ambiguously, the term biophysics is also regularly 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. Nevertheless, other biological sciences also perform research on the biophysical properties of living organisms including molecular biology, cell biology, biophysics, and biochemistry.

Overview

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.

A ribosome is a biological machine that utilizes protein dynamics Protein translation.gif
A ribosome is a biological machine that utilizes protein dynamics

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, [6] populations [7] 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. [8]

History

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. [9] 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. [10]

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. [11]

Focus as a subfield

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.[ citation needed ]

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

Related Research Articles

The following outline is provided as an overview of and topical guide to chemistry:

Physical science is a branch of natural science that studies non-living systems, in contrast to life science. It in turn has many branches, each referred to as a "physical science", together called the "physical sciences".

Quantum chemistry is a branch of chemistry focused on the application of quantum mechanics in physical models and experiments of chemical systems. It is also called molecular quantum mechanics.

Theoretical chemistry academic field

Theoretical chemistry is the branch of chemistry which develops theoretical generalizations that are part of the theoretical arsenal of modern chemistry: for example, the concepts of chemical bonding, chemical reaction, valence, the surface of potential energy, molecular orbitals, orbital interactions, molecule activation, etc.

Computational physics Numerical simulations in physics via computers

Computational physics is the study and implementation of numerical analysis to solve problems in physics for which a quantitative theory already exists. Historically, computational physics was the first application of modern computers in science, and is now a subset of computational science.

Max Planck Institute of Biochemistry

The Max Planck Institute of Biochemistry (MPIB) is a research institute of the Max Planck Society located in Martinsried, a suburb of Munich. The Institute was "founded in 1973 by the merger of three formerly independent institutes: the Max Planck Institute of Biochemistry, the Max Planck Institute of Protein and Leather Research, and the Max Planck Institute of Cell Chemistry ."

The Max Planck Institute for Biophysical Chemistry in Göttingen is a research institute of the Max Planck Society. Currently, 850 people work at the institute, about half of them are scientists.

Molecular biophysics study of biological systems at the molecular level using methods from the physical sciences

Molecular biophysics is a rapidly evolving interdisciplinary area of research that combines concepts in physics, chemistry, engineering, mathematics and biology. It seeks to understand biomolecular systems and explain biological function in terms of molecular structure, structural organization, and dynamic behaviour at various levels of complexity. This discipline covers topics such as the measurement of molecular forces, molecular associations, allosteric interactions, Brownian motion, and cable theory. Additional areas of study can be found on Outline of Biophysics. The technical challenges of molecular biophysics are formidable, and the discipline has required development of specialized equipment and procedures capable of imaging and manipulating minute living structures, as well as novel experimental approaches.

Max Planck Institute for Medical Research

The Max Planck Institute for Medical Research in Heidelberg, Germany, is a facility of the Max Planck Society for basic medical research. Since its foundation, six Nobel Prize laureates worked at the Institute: Otto Fritz Meyerhof (Physiology), Richard Kuhn (Chemistry), Walther Bothe (Physics), André Michel Lwoff, Rudolf Mößbauer (Physics), Bert Sakmann and Stefan W. Hell (Chemistry).

Arieh Warshel chemist, biochemist and biophysicist

Arieh Warshel is an Israeli-American biochemist and biophysicist. He is a pioneer in computational studies on functional properties of biological molecules, Distinguished Professor of Chemistry and Biochemistry, and holds the Dana and David Dornsife Chair in Chemistry at the University of Southern California. He received the 2013 Nobel Prize in Chemistry, together with Michael Levitt and Martin Karplus for "the development of multiscale models for complex chemical systems".

Biophysical chemistry

Biophysical chemistry is a physical science that uses the concepts of physics and physical chemistry for the study of biological systems. The most common feature of the research in this subject is to seek explanation of the various phenomena in biological systems in terms of either the molecules that make up the system or the supra-molecular structure of these systems.

Food physical chemistry is considered to be a branch of Food chemistry concerned with the study of both physical and chemical interactions in foods in terms of physical and chemical principles applied to food systems, as well as the applications of physical/chemical techniques and instrumentation for the study of foods. This field encompasses the "physiochemical principles of the reactions and conversions that occur during the manufacture, handling, and storage of foods"

The following outline is provided as an overview of and topical guide to biophysics:

The following outline is provided as an overview of and topical guide to natural science:

G. Marius Clore Molecular biophysicist, structural biologist

G. Marius Clore FRSC is a British-born, American molecular biophysicist and structural biologist. He was born in London, U.K. and is a dual US/U.K. Citizen. He is a member of the United States National Academy of Sciences, a NIH Distinguished Investigator, and the Chief of the Protein NMR Spectroscopy Section in the Laboratory of Chemical Physics of the National Institute of Diabetes and Digestive and Kidney Diseases at the U.S. National Institutes of Health. He is known for his foundational work in three-dimensional protein and nucleic acid structure determination by biomolecular NMR spectroscopy, for advancing experimental approaches to the study of large macromolecules and their complexes by NMR, and for developing NMR-based methods to study rare conformational states in protein-nucleic acid and protein-protein recognition.

Klaus Schulten was a German-American computational biophysicist and the Swanlund Professor of Physics at the University of Illinois at Urbana-Champaign. Schulten used supercomputing techniques to apply theoretical physics to the fields of biomedicine and bioengineering and dynamically model living systems. His mathematical, theoretical, and technological innovations led to key discoveries about the motion of biological cells, sensory processes in vision, animal navigation, light energy harvesting in photosynthesis, and learning in neural networks.

Laura B. Eisenstein (1942-1985) was a Professor in the Physics department at the University of Illinois until her early death. Eisenstein was known for her contributions to the understanding of light-energy transduction mechanisms in biological molecules and their higher order assemblies. She was an experimentalist and spectroscopist who was particularly well known for her contributions applying the techniques of x-ray absorption spectroscopy and time-resolved resonance Raman spectroscopy to the study of biomolecules. These studies indicated that phenomena such as quantum-mechanical tunnelling can be successfully investigated even in soft-matter systems like proteins.

David N. Beratan is the R.J. Reynolds Professor of Chemistry at Duke University. He has secondary appointments in the departments of Physics and Biochemistry. He is the Director of the Center for Synthesizing Quantum Coherence, a NSF Phase I Center for Chemical Innovation.

References

  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   3055214 . 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. Sahai, Erik; Trepat, Xavier (July 2018). "Mesoscale physical principles of collective cell organization". Nature Physics. 14 (7): 671–682. doi:10.1038/s41567-018-0194-9. ISSN   1745-2481.
  7. Popkin, Gabriel (2016-01-07). "The physics of life". Nature News. 529 (7584): 16. doi:10.1038/529016a. PMID   26738578.
  8. Feynman RP (December 1959). "There's Plenty of Room at the Bottom". Archived from the original on 2010-02-11. Retrieved 2017-01-01.
  9. Franceschetti DR (15 May 2012). Applied Science. Salem Press Inc. p. 234. ISBN   978-1-58765-781-8.
  10. Rosen J, Gothard LQ (2009). Encyclopedia of Physical Science. Infobase Publishing. p. 4 9. ISBN   978-0-8160-7011-4.
  11. 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   3286818 . PMID   22375127.

Sources