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Medical Term:


Pronunciation: en'zim

Definition: A macromolecule that acts as a catalyst to induce chemical changes in other substances, while itself remaining apparently unchanged by the process. Enzymes, with the exception of those discovered long ago (pepsin, emulsin), are generally named by adding -ase to the name of the substrate on which the enzyme acts (glucosidase), the substance activated (hydrogenase), and/or the type of reaction (oxidoreductase, transferase, hydrolase, lyase, isomerase, ligase or synthetase—these being the six main groups in the Enzyme Nomenclature Recommendations of the International Union of Biochemistry). For individual enzymes not listed below, see the specific name.

Synonym(s): organic catalyst1

[G. + L. en, in + zyme, leaven]

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