ENZYME (Gr. ἔνζυμος, leavened, from ἐν, in, and ζύμη, leaven), a term, first suggested by Kühne, for an unorganized ferment (see Fermentation), a group of substances, in the constitution of plants and animals, which decompose certain carbon compounds occurring in association with them. See also Plants: Physiology; Nutrition, &c.