Definition of oxidase in US English:



  • An enzyme which promotes the transfer of a hydrogen atom from a particular substrate to an oxygen molecule, forming water or hydrogen peroxide.

    with modifier ‘cytochrome oxidase’
    • ‘Polyphenol oxidase is the enzyme that makes phenolics react to form brown pigments.’
    • ‘Respiration in wheat endosperm was measured together with the activities of citrate synthase and cytochrome oxidase.’
    • ‘Briefly, plasma lactic acid is converted to pyruvate and hydrogen peroxide by lactate oxidase.’
    • ‘Despite many important advances in the understanding of terminal oxidases, the mechanism by which the electron transfer events are coupled to proton translocation is unknown.’
    • ‘First, peroxidases and oxidases follow a different time-course of induction during wound healing.’


Late 19th century: from French oxydase, from oxyde ‘oxide’.