organic substances of protein nature, which are synthesized in the cells and many times speed up running in them a reaction, without being subjected to chemical transformations. Substances that have a similar effect, exist in inanimate nature and are called catalysts. Enzymes (from lat. fermentum - fermentation, leaven) is sometimes called enzymes (from the Greek. en - inside, zyme - leaven). All living cells contain a very large set of enzymes from the catalytic activity of which depends on the functioning of the cells. Virtually every a variety of reactions in the cell requires the participation of a specific enzyme. A study of the chemical properties of enzymes and their catalyzed reactions is engaged in a special, very important area of biochemistry - Enzymology. Many enzymes are in a cage in the free state, being simply dissolved in the cytoplasm; others are associated with complex highly organized structures.