Pääentsyymiluokka

Pääentsyymiluokka is a classification system used in biochemistry to categorize enzymes into broad groups based on the type of reaction they catalyze. This system divides all known enzymes into seven main classes, each designated by a number from 1 to 7. These classes are further subdivided into subclasses, sub-subclasses, and finally individual enzyme entries, identified by a unique four-digit EC number.

The seven main classes of enzymes are: Oxidoreductases (EC 1), Transferases (EC 2), Hydrolases (EC 3), Lyases (EC 4), Isomerases (EC 5), Ligases (EC 6), and Translocases (EC 7). Oxidoreductases catalyze oxidation and reduction reactions, while Transferases move functional groups from one molecule to another. Hydrolases cleave bonds using water, and Lyases add or remove groups from double bonds. Isomerases catalyze intramolecular rearrangements, and Ligases join two molecules together, typically with the energy supplied by ATP hydrolysis. The newest class, Translocases, are involved in the movement of molecules across membranes.

The EC number system is maintained by the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology. It provides a standardized and unambiguous way to refer to specific enzymes, facilitating communication and research across different laboratories and disciplines. Each enzyme is assigned a unique EC number based on the specific chemical reaction it catalyzes, regardless of its origin or protein structure. This systematic classification is crucial for understanding metabolic pathways, drug development, and industrial applications of enzymes.