Enzymology. The class of all enzymes catalyzing oxidation-reduction reactions. The substrate that is oxidized and loses electrons is regarded as electron donor; the substrate that is reduced and gains electrons is called electron acceptor.
The recommended name will be dehydrogenase, wherever this is possible (e.g., lactate dehydrogenase); as an alternative, reductase can be used (e.g., glutathione reductase). Oxidase is only used in cases where O2 is the acceptor and hydrogen peroxide is built (e.g., xanthine oxidase).