isoenzyme

isoenzyme /ī′sō·en″zīm/ [Gk, isos + en, in, syme, ferment] , a chemically distinct form of an enzyme. The various forms are distinguishable in analysis of blood samples, which aids in the diagnosis of disease. Different enzymes that catalyze the same physiological reaction may also exist as isoenzymes in different animal species. Also called isozyme.