Biochemistry

In a living cell, many chemical reactions of multidirectional action can be simultaneously carried out: some lead to the splitting of complex organic substances into simpler ones with the extraction of chemical energy, while others, with the expenditure of energy, lead to the biosynthesis of biopolymers. Enzymes that catalyze these reactions are organized into enzyme systems (multienzyme systems) that cause several consecutive reactions (from 2 to 20 or more). The metabolic reactions that occur in the cell under the action of enzymes are strictly regulated: only the number of different types of simple molecules is synthesized, which is necessary for the biosynthesis of proteins, nucleic acids, lipids, polysaccharides, etc. Such self-regulation provides a certain stationary state of the living structure even in cases significant changes in the environment. Due to enzyme systems, the cell is able to maintain itself in constant dynamic equilibrium and tune in to work in a mode of maximum component saving. The processes taking place in living organisms far exceed the capabilities of modem chemical technologies. Currently, fermentology, which has become one of the main developing branches of biochemistry, has achieved significant results. About 2000 enzymes were discovered, of which 200 were obtained in crystalline form. 3.2 STRUCTURE OF ENZYMES According to the chemical structure, enzymes are simple (enzyme-proteins) and complex proteins (enzyme-proteids) . Protein enzymes arc composed only of amino acid residues, so they are called single-component. Complex enzymes, in addition to protein, contain a non-protein part, so they are called two-component. The protein part of a complex enzyme is called an apoenzyme (carrier), non-protein - an additional, prosthetic group, coenzyme or coenzyme (active part). The common name for a complex enzyme is holoenzyme (from the Greek. Holos - the whole). Apoenzyme is thermolabile, like all proteins, a coenzyme is thermally stable. Complex enzymes are characterized by the fact that neither the apoenzyme nor the coenzyme separately possess pronounced catalytic activity. Only a complex of protein and non-protein parts exhibits enzymatic properties. Moreover, the protein component is responsible for the specificity of the enzyme and significantly increases the catalytic properties of the non-protein group. At the same time, the additional group determines the activity of the action and 80