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A protein that speeds up chemical reactions in the body.

Definition from: Physician Data Query via Unified Medical Language SystemThis link leads to a site outside Genetics Home Reference. at the National Library of Medicine

An enzyme is a biological catalyst and is almost always a protein. It speeds up the rate of a specific chemical reaction in the cell. The enzyme is not destroyed during the reaction and is used over and over. A cell contains thousands of different types of enzyme molecules, each specific to a particular chemical reaction.

Definition from: Talking Glossary of Genetic TermsThis link leads to a site outside Genetics Home Reference. from the National Human Genome Research Institute

Related discussion in the Handbook

See also Understanding Medical Terminology.

Published: October 5, 2015