Biochemistry involves the use of chemistry's tools and principles to explore living systems. Biochemists investigate the structure and physical properties of biological molecules like proteins and nucleic acids, the workings of enzymes, chemical regulation, the chemistry of inheritance, vitamins, energy use within cells, and more. Related fields include biophysics, which applies physics techniques to biology, and cell biology, which examines the organization and function of cells. Molecular biology, a term from 1950, overlaps with biochemistry, focusing on molecular organization. Biochemistry is also known as physiological or biological chemistry.In terms of history, the foundation of modern chemistry was laid by Antoine-Laurent Lavoisier (1743-1794), who studied chemical oxidation and its relation to respiration. In the 19th century, Justus von Liebig advanced organic chemistry in Germany after studying in Paris. Louis Pasteur identified yeasts and bacteria as agents of fermentation and disease, using chemical methods to study them. By 1877, these ferments were named enzymes. The protein nature of enzymes was clarified in 1926 when urease, a pure crystalline enzyme, was isolated.The role of vitamins in preventing diseases like beriberi became clear in 1935 when a vitamin was found to be part of an enzyme. In 1929, ATP was isolated from muscle, linking ATP production with cellular respiration; by 1940, F.A. Lipmann recognized ATP as a key energy exchange molecule in cells. The use of radioisotopes for tracing chemical pathways in the body began in 1935, thanks to R. Schoenheimer and D. Rittenberg.DNA's journey began in 1869 when nucleic acid was isolated from cell nuclei; its role as genetic material was discovered in 1944, when bacterial DNA was shown to alter other bacteria's genetic material. The double helix structure of DNA, proposed by Watson and Crick within a decade, explained DNA's genetic function.
