zymogen

Zym"o*gen, n. Etym: [Zyme + -gen.] (Physiol. Chem.) Defn: A mother substance, or antecedent, of an enzyme or chemical ferment; -- applied to such substances as, not being themselves actual ferments, may by internal changes give rise to a ferment. The pancreas contains but little ready-made ferment, though there is present in it a body, zymogen, which gives birth to the ferment. Foster.

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