oksidaz

Oksidaz, or oxidase in English, designates a group of enzymes that catalyze oxidation–reduction reactions in which molecular oxygen (O2) is the terminal electron acceptor. The term is used in several languages (spelled oksidaz, oksydaza, oksidase, etc.) and generally refers to enzymes that remove electrons from substrates and transfer them to O2, yielding water or hydrogen peroxide.

Oxidases are a subset of oxidoreductases and include a wide range of enzymes, often categorized by their prosthetic groups (flavin- or heme-containing, copper-containing) and substrates. Examples include glucose oxidase (converts glucose to gluconolactone with H2O2 production), lactate oxidase, xanthine oxidase, urate oxidase, and cytochrome c oxidase (a key component of mitochondrial respiration). Some oxidases are soluble enzymes in bacteria or fungi; others are membrane-bound, such as cytochrome c oxidase in the mitochondrial inner membrane.

Distinctions: oxidases typically transfer electrons from the substrate to O2 without incorporating oxygen into the substrate, generating water or hydrogen peroxide. By contrast, oxygenases incorporate oxygen atoms into substrates; the two classes are related but distinct.

Applications: oxidases are used in clinical tests (oxidase test for bacterial identification), biosensors, and industrial biocatalysis. Glucose oxidase is widely used in glucose monitoring and food preservation, among others.

See also: oxidoreductase, oxidase test, enzyme classification (EC).