active site

noun

: a region on the surface of an enzyme whose shape permits binding only of a specific molecular substrate that then undergoes catalysis

Examples of active site in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
To find out whether this activity could be improved, the researchers identified amino acids that were in close proximity to the active site of the protease, but not actively involved with the catalysis. — ArsTechnica, 14 Oct. 2026 This indicated a stronger interaction at its iron active site. — Georgina Jedikovska, Interesting Engineering, 29 Sep. 2026 The location of the original Govan Old Parish Church was an active site of worship from the 5th century AD until 2007. — Leigh Anne Miller, ARTnews.com, 9 Apr. 2026 At the detention center Alligator Alcatraz remained an active site the morning after Williams’ ruling. — Ana Ceballos, Miami Herald, 22 Aug. 2025 See All Example Sentences for active site

Word History

First Known Use

1957, in the meaning defined above

Time Traveler
The first known use of active site was in 1957

Rhymes for active site

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Browse Nearby Words

active shooter
active site
active suspension
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Cite this Entry

“Active site.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/active%20site. Accessed 20 Oct. 2026.

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Medical Definition

active site

noun
: a region especially of a biologically active protein (as an enzyme) where catalytic activity takes place and whose shape permits the binding only of a specific reactant molecule

More from Merriam-Webster on active site

Britannica.com: Encyclopedia article about active site

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