Term: lyases https://doi.org/10.1351/goldbook.L03652 Definition: enzymes cleaving C–C, C–O, C–N and other bonds by other reactions than by hydrolysis or oxidation. Lyases catalyse the addition of molecules to unsaturated compounds or the elimination of molecules creating an unsaturated residue. Related Terms: 1) enzymes (http://doi.org/10.1351/goldbook.E02159). 2) hydrolysis (http://doi.org/10.1351/goldbook.H02902). 3) oxidation (http://doi.org/10.1351/goldbook.O04362). 4) elimination (http://doi.org/10.1351/goldbook.E02038). Source: PAC, 1992, 64, 143. 'Glossary for chemists of terms used in biotechnology (IUPAC Recommendations 1992)' on page 159 (https://doi.org/10.1351/pac199264010143) Citation: 'lyases' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.L03652 License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.