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

The scientists also identified a potentially important connection between humanin and an enzyme called Nox2, which helps generate reactive oxygen species.

From Science Daily ● Oct. 25, 2026

One of the most important discoveries concerns TET2, an enzyme that helps prevent cancerous growth by controlling whether particular genes are switched "on" or "off."

From Science Daily ● Oct. 20, 2026

They found that excessive fibronectin interferes with communication between cells by activating abnormal signals through integrins, proteins that help cells sense and respond to their surroundings, and an enzyme known as focal adhesion kinase.

From Science Daily ● Oct. 19, 2026

Their analysis included liver enzyme measurements, body mass index, blood lipid levels, and other indicators of metabolic health.

From Science Daily ● Oct. 19, 2026

The toxin does the deed insidiously, indirectly, by inhibiting an enzyme essential to glycoprotein metabolism.

From "Into the Wild" by Jon Krakauer

BFT belongs to a class of enzymes called proteases, which cut other proteins.

From Science Daily ● Oct. 31, 2026

"Vitamin C is important because it is involved in a range of biological functions, including the activity of enzymes that regulate normal cell function."

From Science Daily ● Oct. 20, 2026

Although it resembled esterases, which are known for breaking down ester bonds, it also shared structural similarities with another important family of bacterial enzymes: beta-lactamases.

From Science Daily ● Oct. 16, 2026

Some polymers contain bonds that microbial enzymes can attack, allowing bacteria to dismantle them into smaller molecules.

From Science Daily ● Oct. 16, 2026

When bacteria switched from glucose to lactose consumption, they induced specific lactose-digesting enzymes.

From "The Gene" by Siddhartha Mukherjee

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