enzyme

enzyme — noun

1. a protein produced inside a living cell that speeds up a chemical reaction in th

1.nounB2
Definition

a protein produced inside a living cell that speeds up a chemical reaction in the body without being used up or changed during the process

Example

Roya learned in biology class that the enzyme in saliva helps break down starch into sugar.

enzyme + breaks down [substance] — typical verb-object pattern

Without the right enzyme, Niran's body cannot digest milk products properly.

adjective + enzyme for a specific function: right enzyme

Common collocations
  • digestive enzyme
  • liver enzyme
  • specific enzyme
  • produce an enzyme
  • block an enzyme
  • activate an enzyme
  • enzyme activity
  • enzyme deficiency
Synonyms
  • biological catalyst

    broader descriptive phrase; any catalyst found in living systems, not limited to proteins

  • catalyst

    much broader — includes non-biological substances; enzymes are a subset of catalysts that are proteins made by cells

Grammar Patterns

adjective + enzyme (digestive / specific / liver enzyme)

enzyme + verb (breaks down / speeds up / catalyses)

Usage Note

Often followed by a description of what the enzyme breaks down or speeds up. The most common verbs paired with this sense are produce, release, block, activate, and break down.

Common Mistakes

The enzyme can help to speed up the reaction catalysed by the enzyme itself.
The enzyme speeds up the chemical reaction without being changed by it.
avoid circular wording; enzymes speed up reactions, not themselves.
My body does not have the protein to digest milk.
My body does not have the enzyme needed to digest milk.
not all proteins are enzymes; use 'enzyme' when referring to a substance that speeds up a specific reaction.

Word family

  • enzymatic
    adjectiveC1
  • enzymology
    nounC1

Synonym discussion

Sense: noun/1

An enzyme is a specific type of protein that speeds up a chemical reaction in a living body without being consumed. A catalyst is a broader term — it includes any substance that accelerates a reaction, including non-biological ones like metal catalysts in industry. All enzymes are proteins, but not all proteins are enzymes: structural proteins like collagen and transport proteins like haemoglobin do not catalyse reactions. Hormones are signalling molecules (often also proteins) that are produced in one part of the body and travel to another part to trigger a response; they do not speed up chemical reactions themselves. For example, lactase (an enzyme) breaks down lactose in the gut, whereas insulin (a hormone) tells cells to absorb sugar from the blood.

enzyme ↗catalyst ↗protein ↗hormone ↗

Common collocations

Nouns

Adverbs

Phrases

  • lack of an enzyme
  • enzyme in the body
  • type of enzyme

Prepositions

  • in (the liver / saliva / the body)
  • without (an enzyme)

Etymology

GreekGermanEnglish

The word comes from Greek 'enzymos' meaning 'leavened' — from 'en-' (in) and 'zyme' (leaven / yeast). German scientist Wilhelm Kühne first used 'enzym' in 1878 to describe substances in yeast that cause chemical changes. English borrowed the term in the late 19th century as 'enzyme'.