Biochemistry

In the active center, the enzyme molecules come together, forming functional groups, which is possible only as a result of a very definite coagulation of the polypeptide chain. If there are charged groups in the substrate, the formation of the FS complex occurs due to the electrostatic interaction of ionic bonds between positively charged groups of the enzyme, and vice versa. If the substrate does not have charged groups, then the attachment of the enzyme to the substrate occurs due to the formation of hydrogen bonds or hydrophobic interaction. Cofactors, performing a catalytic function, remain chemically unchanged as a result of the catalytic reaction. 3.5 REGULATION OF ENZYMATIC REACTIONS Enzyme activity is due to various factors. For example, a deficiency of vitamins leads to a disruption in the synthesis of coenzymes, as a result of which the corresponding biochemical processes are disrupted. The composition and activity of enzymes depends on the nature of the food. I.P.Pavlov and his students found that when feeding dogs meat, the enzymatic activity and acidity of their gastric juice is much higher than when feeding milk. Prolonged and excessive feeding of certain amino acids, for example, tryptophan, to staiving animals caused the replacement of some amino acids in the aldolase enzyme molecule with others, which entailed a change in the structure and function of the enzymes. These data indicate the adaptive ability of the body to a certain nature of nutrition by changing the composition of digestive juices. Enzymes that are constantly present in the body are called constitutional. Under certain conditions, new enzymes are formed in the body. They are called adaptive. Thus, feeding tyrosine to animals enhances the synthesis of the tyrosin aminotransferase enzyme. With an increased protein content in the diet, the activity of the enterokinase enzyme, which catalyzes the cleavage of peptides, as well as the conversion of trypsinogen to trypsin, increases. Trypsin in turn activates the transformation of chymotrypsinogen into chymotrypsin-, Thus, a catalytic chain reaction occurs. In this process, enterokinase plays the role of a trigger mechanism for the adaptation of enzymes that break down proteins. Reducing the amount of protein in the diet first leads to a -weakening of enterokinase activity, and then inhibits the action of trypsin and chymotrypsin. Adaptive enzymes are also called inducible (from Latin inductio - introduction), and substances that contribute to the appearance of inducible enzymes are called inducers. Sometimes an inducer causes the appearance of not 92