Oxidase


In biochemistry, an oxidase is an oxidoreductase that uses dioxygen as the electron acceptor. In reactions involving donation of a hydrogen atom, oxygen is reduced to water or hydrogen peroxide. Some oxidation reactions, such as those involving monoamine oxidase or xanthine oxidase, typically do not involve free molecular oxygen.
The oxidases are a subclass of the oxidoreductases. The use of dioxygen is the only unifying feature; in the EC classification, these enzymes are scattered in many categories.

Examples

An important example is EC 7.1.1.9 cytochrome c oxidase, the key enzyme that allows the body to employ oxygen in the generation of energy and the final component of the electron transfer chain. Other examples are:
In microbiology, the oxidase test is used as a phenotypic characteristic for the identification of bacterial strains; it determines whether a given bacterium produces cytochrome oxidases.
The test is used to determine whether a bacterium is an aerobe or anaerobe. However a bacterium that is oxidase negative is not necessarily anaerobic, it may just indicate the bacterium does not possess cytochrome c oxidase.