enzymklass

Enzymklass, or enzyme class, is a category used in biochemistry to group enzymes by the type of chemical reaction they catalyze. The most widely used framework is the Enzyme Commission (EC) numbering system, which organizes enzymes into six major classes and assigns a hierarchical code to each enzyme.

The six major classes are: oxidoreductases (EC 1) that catalyze oxidation-reduction reactions; transferases (EC 2) that transfer functional groups; hydrolases (EC 3) that catalyze hydrolysis; lyases (EC 4) that cleave or form bonds by means other than hydrolysis or redox, often through elimination or addition to double bonds; isomerases (EC 5) that catalyze rearrangements within a molecule; and ligases (EC 6) that join two molecules with energy input. Examples include alcohol dehydrogenase (oxidoreductase), alanine transaminase (transferase), protease (hydrolase), pyruvate decarboxylase (lyase), triose phosphate isomerase (isomerase), and DNA ligase (ligase).

Purpose and usage: classifying enzymes by their reaction type aids in understanding mechanisms, naming, and functional annotation in biochemistry, molecular biology, and pharmacology. EC numbers are maintained by the International Union of Biochemistry and Molecular Biology (IUBMB) and provide a standardized reference across scientific literature.

Notes: while most enzymes are assigned to a primary class, some exhibit multiple activities or moonlighting functions that span categories. Revisions and updates to classifications occur as new enzymes are discovered or better understood, reflecting advances in enzymology and genomics.