From Big Medical Encyclopedia

CATALYSIS (grech, katalysis destruction) — change of speed of chemical changes under the influence of substances (catalysts) which are entering interaction with reactants, but not being a part of the formed products and remaining not changed upon termination of reaction. For medicine and biology the greatest value has To., carried out at operation of bio-catalysts — enzymes (see. Enzymes ).

Enzymes hold key position in functioning of live organisms. They catalyze practically all chemical transformations which are carried out in wildlife. As examples it is possible to call processes fermentations (see), glycolysis (see), breath, biosynthesis of amino acids, sugars, fat to - t, proteins, nucleinic to - t, lipids. Many patol, the phenomena are caused, eventually, by disturbance of the coordinated action of enzymes defining normal course of processes of life activity.

Catalytic processes are widely used in the industry (synthesis of ammonia, production nitric and sulfuric to - t, receiving synthetic rubber) and at implementation of sintez of various organic compounds. Technological processes in a number of the industries of the food industry (cheese making, winemaking, production of tea) are based on effect of enzymes.

See also Autocatalysis , Inhibitors , Catalysts , Kinetics of biological processes .

Bibliography: Jenks In, the Catalysis in chemistry and enzymology, the lane with English, M., 1972; Dickson M. and Webb E. Enzymes, the lane with English, M., 1966; Ridi of E. K l. Development of representations in the field of a catalysis, the lane with English, M., 1971, bibliogr.

L. M. Ginodman.