oxidasa

Oxidase is an enzyme that catalyzes oxidation-reduction reactions in which molecular oxygen (O2) serves as the terminal electron acceptor. Oxidases belong to the class of oxidoreductases (EC 1) and transfer electrons from a substrate to O2, reducing it to water or hydrogen peroxide. They differ from oxygenases, which incorporate oxygen atoms into the substrate rather than simply transferring electrons to O2.

Many oxidases generate hydrogen peroxide (H2O2) as a byproduct, which can be reactive and has to be detoxified by cellular enzymes such as catalase or peroxidases. The production of H2O2 links oxidase activity to cellular redox balance and defense mechanisms, as well as to potential oxidative damage if not properly managed.

Examples of oxidases include cytochrome c oxidase, a component of the mitochondrial electron transport chain that reduces O2 to water; monoamine oxidases that break down neurotransmitters; xanthine oxidase involved in purine metabolism; and a range of plant and microbial oxidases such as glucose oxidase and lactate oxidase that are used in biosensors, food processing, and industrial applications. Some oxidases participate in pigmentation and defense responses in plants and microbes, oxidizing phenolic substrates with oxygen.

Overall, oxidases play essential roles in energy production, metabolism, detoxification, and biosensing. They are studied in biochemistry, physiology, medicine, and biotechnology for their involvement in cellular respiration, neurotransmitter regulation, oxidative stress, and diagnostic or industrial applications. In microbiology, oxidase activity is sometimes used as a diagnostic criterion to identify certain bacteria.