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

Rennet, an enzyme naturally present in the stomachs of ruminants, would prompt the milk to coagulate, separating into curds and whey, thus laying the groundwork for modern cheese production.

From Salon

In the years since, researchers have come up with a number of underlying factors that might increase a baby’s risk of SIDS, including problems in the part of the brain that controls breathing, abnormal serotonin receptors, and low levels of an enzyme connected to sleep arousal.

From Los Angeles Times

The sometimes painful process can take multiple sessions and is done by injecting an enzyme called hyalase that can cause facial features like lips to bruise and balloon before settling back into their original shape.

From Los Angeles Times

There were also supply issues with alternative brands of pancreatic enzyme replacement therapy medications due to a knock-on increase in demand.

From BBC

All cheesemakers first pump milk into a cheese vat and add a special enzyme called rennet.

From Salon

Related Words

• impetus
• incentive
• motivation
• stimulant