Biophysics
Biophysics is a diverse and eclectic field, and consequently difficult to categorize. For the purpose of this summary of educational resources in biophysics, biophysics is divided into three parts or topic areas: molecular structures, biophysical techniques, and biological mechanisms. Each topic area is defined below and an attempt is made to indicate how these areas are interrelated within the field of biophysics. For an annotated list of specific resources, available as text files or websites, for each topic area, please go here.

Molecular Structures
Biophysics explains the biological functions of cells, tissues, and organisms in terms of the structure and behavior of biological molecules. Genes, the basic elements of biological information, reflect the molecular structures of the enormously large, linear DNA (deoxyribonucleic acid) molecules of which they are made. The behavior of enzymes, hormones, and antibodies reflects the molecular structures of proteins and the organic chemistry of the functional groups of the amino acid side chains. The surface and barrier properties of biological membranes reflect the ability of lipids to aggregate into flexible two-dimensional bilayers with hydrophobic cores and polar surfaces.

Biophysical Techniques
The characterization of molecular structure, the measurement of molecular properties, and the observation of molecular behavior presents an enormous challenge for biological scientists. A wide range of biophysical techniques have been developed to study molecules in crystals, in solution, in cells, and in organisms. These biophysical techniques provide information about the electronic structure, size, shape, dynamics, polarity, and modes of interaction of biological molecules. Some of the most exciting techniques provide images of cells, subcellular structures, and even individual molecules. It is now possible, for example, to directly observe the biological behavior and physical properties of single protein or DNA molecules within a living cell and determine how the behavior of the single molecule influences the biological function of the organism.

Biophysical Mechanisms
Much of the scientific success of biophysics depends upon its ability to develop detailed physical mechanisms to explain specific biological processes. The double helical structure of DNA, for example, provides a framework for an explanation of how genetic material is replicated and how genetic mutations arise: specific proteins mediate the unwinding of the DNA duplex and the assembly of a new strand based on complementary base pairing of the four DNA bases, guanine with cytosine and adenine with thymine; mismatch of one of these base pairs generates a complementary strand with a single base substitution (a mutation). The value of this, and a variety of other biophysical mechanisms, is unlimited for human knowledge in general and for biomedical research in particular.