Apoenzyme vs. Zymogen — What's the Difference?

The protein component of an enzyme, excluding additional components such as cofactors or inhibitors.

A zymogen (), also called a proenzyme (), is an inactive precursor of an enzyme. A zymogen requires a biochemical change (such as a hydrolysis reaction revealing the active site, or changing the configuration to reveal the active site) for it to become an active enzyme.

(enzyme) An inactive haloenzyme lacking a cofactor.

See proenzyme.

A protein that combines with a coenzyme to form an active enzyme

(biochemistry) A proenzyme, or enzyme precursor, which requires a biochemical change (i.e. hydrolysis) to become an active form of the enzyme.

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.

Any of a group of compounds that are inactive precursors of enzymes and require some change (such as the hydrolysis of a fragment that masks an active enzyme) to become active