BIOCHEMISTRY - Main Regulators and Biological Fluids of the Human Body - 2016

1. ENZYMES

1.5. Classification of Enzymes

About 3,000 different Enzymes are known to exist. According to the modern Classification, enzymes are divided into 6 classes.

1. Oxidoreductases. Oxidation-reduction enzymes (180 - 200 enzymes). They catalyze the oxidation or reduction of various chemical substances.

2. Transferases. They catalyze The transfer of various functional groups from one molecule to another, such as phosphorylation and Transamination.

3. Hydrolases. They catalyze Hydrolysis reactions and play a vital role in Digestion. In digestive biochemistry, a key role belongs to enzymes such as Pepsin, Chymotrypsin, schinopeptidase, carboxypeptidase, etc., which break down Proteins as they move along the digestive tract. Carbohydrases catalyze the hydrolysis of Polysaccharides. Amylases are a group of enzymes that hydrolyze starch to form dextrins and maltose. Maltase breaks down maltose. Lipase catalyzes the hydrolysis of fats to yield free Fatty acids and glycerol.

4. Lyases. They catalyze Reactions Involving the Cleavage of C - C, C - O, C - N, C - Hal bonds, and others. Decarboxylases catalyze the removal of СO₂ from organic acids.

5. Isomerases. They catalyze structural rearrangements within a single organic molecule.

6. Ligases. They catalyze The formation of C - O, C - S, C - N, and C - C bonds, building more complex molecules from simpler ones. This group includes enzymes involved in Amino acid METABOLISM and the elongation of the carbon chains of Organic compounds.