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

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

From Science Daily ● Oct. 16, 2026

Its unusually exposed active site also provides space for the enzyme to interact with polymer chains.

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

They proved you could destroy a problematic protein by bringing a smooth protein closer to an enzyme that helps dispose of cell waste—without needing to latch on to the protein like traditional drugs do.

From The Wall Street Journal ● Oct. 15, 2026

They carry not only instructions about eye color, height, nose shape, enzyme production, microphage resistance, but a story, too.

From "Middlesex: A Novel" by Jeffrey Eugenides

For each cell type, the scientists analyzed RNA transcripts, which are produced when cells read genetic instructions from DNA to make proteins, enzymes, and other essential components.

From Science Daily ● Oct. 13, 2026

Their findings suggest that carefully chosen enzymes might someday be used to alter the makeup of dental plaque and help maintain a healthier balance of microorganisms.

From Science Daily ● Oct. 7, 2026

Vitamin C can increase the activity of cellular proteins known as TET enzymes, which help regulate whether certain genes are switched on or off.

From Science Daily ● Oct. 3, 2026

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

From Salon ● Sep. 30, 2026

If a mistake is made, there are enzymes which snip the mistake out and replace the wrong nucleotide by the right one.

From "Cosmos" by Carl Sagan

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