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

Beyond its luminous core, Messier 77 is also a highly active site of star formation. — Bojan Stojkovski, Interesting Engineering, 10 May 2026

The theory also hints at why results have been so inconsistent—creating enough active sites to produce meaningful amounts of heat requires nanoscale control over a metal’s shape. — Michael Koziol, IEEE Spectrum, 28 Nov. 2018

Overall, the simple breaking of one chemical bond has at least four distinct stages and requires multiple amino acids to be positioned within the enzyme's active site with atomic precision. — John Timmer, Ars Technica, 14 Feb. 2025

The number of active sites grew repeatedly during the pandemic, and at one point in late 2022 the riverbed had 130 encampments, the highest total on record. — Blake Nelson, San Diego Union-Tribune, 1 June 2025

Word History

First Known Use

1957, in the meaning defined above

Rhymes for active site

• actinolite
• adipocyte
• amphibolite
• anorthosite
• anthophyllite
• aragonite
• carbonatite
• cassiterite
• chalcopyrite
• cristobalite
• crocidolite
• diatomite

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