Classically, one of a group of enzymes, now termed oxidoreductases (EC class 1), that bring about oxidation by the addition of oxygen to a metabolite or by the removal of hydrogen or of one or more electrons. Oxidase is now used for those cases in which O2 acts as an acceptor (of H or of electrons); those removing hydrogen are now termed dehydrogenases. For individual oxidases, see the specific names.
direct oxidase, originally, an oxidase catalyzing the transfer of O2 directly to other bodies; now termed oxygenase.
indirect oxidase, originally, an oxidase that acts by reducing a peroxide; now termed peroxidase.
terminal oxidase, the last protein in the electron transport, respiratory chain. In mammals this is cytochrome c oxidase.
Any of the enzymes that catalyze biological oxidation.Oxidase is an enzyme which is capable of adding oxygen to a substance, where hydrogen is usually released as a by-product which can bind with oxygen to form water.