enzyme

American  

[en-zahym] / ˈɛn zaɪm /

noun

Biochemistry.

• enzymes
  plural

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  

/ ˈɛnzaɪm, -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

Derived Forms

• enzymatic
  adjective

Inflected Forms

Nouns

• enzymes
  plural

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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

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Explanation

An important element in human chemistry, an enzyme is a protein manufactured by a cell, and is a catalyst in various biological functions. For example, enzymes help break down larger molecules of starch, fat, and protein during digestion. The word enzyme was coined by a German physiologist in the late 1800s to name a digestive process that scientists had been observing. The word was later given to the actual agents discovered to spark the reactions, taken from the Greek énzymos, which meant "leavened." (Leavening makes bread rise.) Remember that the word enzyme is spelled with a y and not an i, which makes sense, since when scientists observe chemical processes, they often ask "why?"

Example Sentences

See Examples For:

enzyme enzymes

Its genetic instructions included a secretion signal that directs the enzyme outside the cell, along with a lipid anchor that holds it firmly to the cell membrane.

From Science Daily ● Oct. 16, 2026

What made this particular enzyme especially interesting was how it was positioned on bacterial cells.

From Science Daily ● Oct. 16, 2026

Laboratory experiments confirmed that the newly discovered enzyme was capable of performing both types of chemical reactions.

From Science Daily ● Oct. 16, 2026

The E3 ligase enzyme cleans up the cell, tagging proteins that are damaged or misfolded for destruction.

From The Wall Street Journal ● Oct. 15, 2026

The only way to eradicate transformation was to digest the material with an enzyme that, of all things, degraded DNA.

From "The Gene" by Siddhartha Mukherjee

This approach allowed them to search for genes that might produce enzymes capable of breaking apart plastic polymers.

From Science Daily ● Oct. 16, 2026

These enzymes are well known for their role in antibiotic resistance.

From Science Daily ● Oct. 16, 2026

The finding raises the possibility that some enzymes involved in plastic decomposition could also contribute to antibiotic resistance.

From Science Daily ● Oct. 16, 2026

All the more reason to pour cold water on outrageous claims about flagging little enzymes in huge databases.

From Salon ● Sep. 30, 2026

Since mutations are random nucleotide changes, most of them are harmful or lethal, coding into existence nonfunctional enzymes.

From "Cosmos" by Carl Sagan

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