enzyme

[ en-zahym ]

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.

enzyme

/ 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

enzyme

/ 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.

enzyme

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.

Derived Forms

• enzymatic, adjective

Word History and Origins

Origin of enzyme¹

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

Word History and Origins

Origin of enzyme¹

C19: from Medieval Greek enzumos leavened, from Greek en- ² + zumē leaven

Example Sentences

As the researchers demonstrate, the interplay of two proteins -- the ion channel TPC2 and the enzyme Rab7a -- plays a decisive role, as they promote the growth and metastasis of melanoma.

From Science Daily

Renin is a hormone enzyme that is produced by cells in the kidney which are stimulated when blood pressure drops.

From Science Daily

Protein design aims to create customized antibodies for therapies, biosensors for diagnostics, or enzymes for chemical reactions.

From Science Daily

Copper is an essential cofactor for a variety of enzymes that play a role in the growth and development of cells.

From Science Daily

An enzyme called EZH2 has an unexpected role in driving aggressive tumor growth in treatment-resistant prostate cancers, according to a new study by scientists at Weill Cornell Medicine.

From Science Daily

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