Try Our Apps


Avoid these words. Seriously.


[en-zahym] /ˈɛn zaɪm/
noun, Biochemistry.
any of various proteins, as pepsin, originating from living cells and capable of producing certain chemical changes in organic substances by catalytic action, as in digestion.
Compare -ase.
Origin of enzyme
1880-85; < Medieval Greek énzymos leavened (Greek en- en-2 + zȳ́m(ē) leaven + -os adj. suffix) Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
Cite This Source
Examples from the Web for enzyme
Contemporary Examples
Historical Examples
  • If the products are removed, the action will continue, if the enzyme is not destroyed.

    The Fundamentals of Bacteriology Charles Bradfield Morrey
  • The enzyme must be specific for the protein since these differ in constitution.

    The Fundamentals of Bacteriology Charles Bradfield Morrey
  • By adding the enzyme maltase from yeast to a forty per cent.

  • Here a similar action is caused by an enzyme called ptyalin.

    A Civic Biology George William Hunter
  • This exchange appears to be aided by the presence of an enzyme in the lung tissues.

    A Civic Biology George William Hunter
British Dictionary definitions for enzyme


any of a group of complex proteins or conjugated proteins that are produced by living cells and act as catalysts in specific biochemical reactions
Derived Forms
enzymatic (ˌɛnzaɪˈmætɪk; -zɪ-), enzymic (ɛnˈzaɪmɪk; -ˈzɪm-) adjective
Word Origin
C19: from Medieval Greek enzumos leavened, from Greek en-² + zumē leaven
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
Word Origin and History for enzyme

1881, as a biochemical term, from German Enzym, coined 1878 by German physiologist Wilhelm Kühne (1837-1900), from Modern Greek enzymos "leavened," from en "in" (see en- (2)) + zyme "leaven" (see zymurgy).

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
enzyme in Medicine

enzyme en·zyme (ěn'zīm)
Any of numerous proteins or conjugated proteins produced by living organisms and functioning as specialized catalysts for biochemical reactions.

en'zy·mat'ic (-zə-māt'ĭk) adj.
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
enzyme in Science

Any of numerous proteins produced in living cells that accelerate or catalyze the metabolic processes of an organism. Enzymes are usually very selective in the molecules that they act upon, called substrates, often reacting with only a single substrate. The substrate binds to the enzyme at a location called the active site just before the reaction catalyzed by the enzyme takes place. Enzymes can speed up chemical reactions by up to a millionfold, but only function within a narrow temperature and pH range, outside of which they can lose their structure and become denatured. Enzymes are involved in such processes as the breaking down of the large protein, starch, and fat molecules in food into smaller molecules during digestion, the joining together of nucleotides into strands of DNA, and the addition of a phosphate group to ADP to form ATP. The names of enzymes usually end in the suffix -ase.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
enzyme in Culture
enzyme [(en-zeyem)]

A protein molecule that helps other organic molecules enter into chemical reactions with one another but is itself unaffected by these reactions. In other words, enzymes act as catalysts for organic biochemical reactions.

The New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source

Word of the Day

Nearby words for enzyme

Difficulty index for enzyme

Most English speakers likely know this word

Word Value for enzyme

Scrabble Words With Friends