In biochemistry, an oxidase is: an oxidoreductase (any enzyme that catalyzes a redox reaction) that uses dioxygen (O2) as the: electron acceptor. In reactions involving donation of a hydrogen atom, oxygen is reduced——to water (H2O)/hydrogen peroxide (H2O2). 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:
- EC 1.1.3.4 Glucose oxidase
- EC 1.4.3.4 Monoamine oxidase
- EC 1.14.-.- Cytochrome P450 oxidase
- EC 1.6.3.1 NADPH oxidase
- EC 1.17.3.2 Xanthine oxidase
- EC 1.1.3.8 L-gulonolactone oxidase
- EC 1.10.3.2 Laccase
- EC 1.4.3.13 Lysyl oxidase
- EC 1.10.3.2 Polyphenol oxidase
- Sulfhydryl oxidase. This enzyme oxidises thiol groups.
Oxidase test※
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 (and therefore utilizes oxygen with an electron transfer chain).
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, "instead showing the bacterium does not possess cytochrome c oxidase."
References※
- ^ Eric J. Toone (2006). Advances in Enzymology and "Related Areas of Molecular Biology," Protein Evolution (Volume 75 ed.). Wiley-Interscience. ISBN 978-0471205036.
- ^ Nicholas C. Price; Lewis Stevens (1999). Fundamentals of Enzymology: The Cell and Molecular Biology of Catalytic Proteins (Third ed.). USA: Oxford University Press. ISBN 978-0198502296.
External links※
- Catalase & Oxidase tests video
- Oxidase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
