biophysics

Scope and methods of biophysics

Biophysics is the branch of science concerned with the experimental and theoretical study of biological system using the background and concept of physics.

It is a molecular science. It seeks to explain biological functions in terms of molecular structures and properties of specific molecules. The size of these molecules varies from small fatty acids and sugars to macromolecules like protein and elongated DNA molecules. These molecules, the sole building blocks of living organisms assemble cells, tissues, organs.

Biophysics has been classified as:

1. Molecular Biophysics

2. Biophysics of cell

3. Biophysics of complex system 

Molecular Biophysics
It is concerned with the study of the structure and physiochemical properties of biologically functional molecules; biopolymers, proteins and nucleic acids. Its objective is to disclose the physical mechanism responsible for the biological functionality of the molecules
say for catalytic activity of protein enzymes. Molecular biophysics can't be separated from molecular biology and chemistry. Molecular biophysics rests on biochemical disciplines and as well as physics of small and large molecules.

The theoretical apparatus of molecular
biophysics consists of equilibrium thermodynamics, statistical mechanics and
quantum mechanics.

The first group includes methods employed in  macromolecular physics for the determination
of molecular masses, sizes and shapes- sedimentation in the ultra centrifuge, scattering of light and X-rays by collision of the substances to be studied etc.

The second group includes method used for investigation of molecular structure based on interaction of matter with light from X- rays to radiofrequency radiation .NMR ( Nuclear Magnetic Resonance) and EPR( Electron Paramagnetic resonance) important
calorimetric methods for macromolecules.

The third group includes calorimetric methods used for the study of the conversion of biological macromolecules. Finally the structure of proteins and nucleic acids are directly studied by means of electron microscopy.

Biophysics of cells:

It deals with the structure and function of cell and tissue system. It includes the study of the physics of biological membranes and bioenergetics processes. The study of the generation and transmission of nerve impulses, mechanochemical process (muscles contraction), photo biological phenomena (photosynthesis, vision) comes under this category.

Biophysics of complex system

This branch of biophysics is a theoretical branch devoted to general physico-biological problems and physico-mathematical modeling of biological process.

Following are the sections related to it:

a. The general theory of dissipative non linear dynamical system- the thermodynamics of irreversible process and kinetic modeling

b. The theory of excitable media, which includes the theory of biological oscillatory processes.

c. The general theoretical treatment of bioenergetics phenomena.

d. The general theory and modeling of the processes of biological development, including various approaches to these phenomena based on information theory.