enzyme

American  

[en-zahym] / ˈɛn zaɪm /

noun

Biochemistry.

1. 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.

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enzyme British  

/ ɛnˈzaɪmɪk, ˈɛnzaɪm, ˌɛnzaɪˈmætɪk, -zɪ-, -ˈzɪm- /

noun

1. any of a group of complex proteins or conjugated proteins that are produced by living cells and act as catalysts in specific biochemical reactions

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enzyme Scientific  

/ ĕn′zīm /

1. 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.

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enzyme Cultural  

1. A protein molecule that helps other organic molecules (see also organic molecule) 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.

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Other Word Forms

• enzymatic adjective

Etymology

Origin of enzyme

First recorded in 1880–85; from Medieval Greek énzymos “leavened,” from Greek en- en- ² + zȳ́m(ē) “leaven” + -os, adjective suffix

Example Sentences

Scientists have uncovered a surprising risk linked to blocking a cellular enzyme once believed to protect against fatty liver disease.

From Science Daily

The change was driven less by the bacteria themselves and more by enzymes already present in the wheat.

From Science Daily

Nature is one of the richest sources of useful enzymes, yet many remain undiscovered.

From Science Daily

This bacterium contains the enzyme needed to produce serotonin.

From Science Daily

The enzyme needed to produce CoA is located mainly outside mitochondria.

From Science Daily

Related Words

• impetus
• incentive
• motivation
• stimulant