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  

/ 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

Derived Forms

• enzymatic
  adjective

Inflected Forms

Nouns

• enzymes
  plural

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

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

The enzyme is active in organs including the heart and the brain, where it helps support normal nerve cell function.

From Science Daily ● Aug. 17, 2026

It kills weeds by blocking an enzyme involved in photosynthesis.

From Science Daily ● Aug. 6, 2026

The researchers reasoned that the same enzyme might produce other peptides that influence energy balance and appetite.

From Science Daily ● Jul. 24, 2026

As the body attempts to clear methanol - breaking it down or metabolising it in the liver - an enzyme converts it to formaldehyde and formic acid.

From BBC ● Jul. 18, 2026

Just one enzyme misfiring, just one wrong protein activation, and you could have cancer.

From "The Immortal Life of Henrietta Lacks" by Rebecca Skloot

By tracing the origins of enzymes during the earliest split between bacteria and archaea, the researchers found evidence that free-living cells may have originated independently twice.

From Science Daily ● Aug. 12, 2026

Within each lineage, newly evolved enzymes gradually replaced the inorganic catalysts supplied by the environment where metabolism had first developed.

From Science Daily ● Aug. 12, 2026

He said it "allows us to dream of exciting possibilities for tackling humanity's greatest challenges" such as developing phages to tackle disease, enzymes to treat genetic disorders and antibodies that could be used in immunotherapy.

From BBC ● Aug. 6, 2026

The enzymes helped shape the molecule into its complicated final structure.

From Science Daily ● Aug. 3, 2026

It is from the progeny of this parent cell that we take our looks; we still share genes around, and the resemblance of the enzymes of grasses to those of whales is a family resemblance.

From "The Lives of a Cell" by Lewis Thomas

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