Science, Tech, Math › Science What Is a Thiol Group? Definition and Examples Share Flipboard Email Print This is the chemical structure of cysteine. The yellow SH on the left hand side is a thiol group. Todd Helmenstine Science Chemistry Chemical Laws Basics Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Anne Marie Helmenstine, Ph.D. Facebook Twitter Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. Learn about our Editorial Process Updated on May 14, 2018 Definition: A thiol group is a fuctional group containing a sulfur atom bonded to a hydrogen atom. General formula: -SH Also Known As: sulfanyl group, mercapto group Examples: The amino acid cysteine contains a thiol group. Cite this Article Format mla apa chicago Your Citation Helmenstine, Anne Marie, Ph.D. "What Is a Thiol Group?" ThoughtCo, Aug. 25, 2020, thoughtco.com/definition-of-thiol-group-605735. Helmenstine, Anne Marie, Ph.D. (2020, August 25). What Is a Thiol Group? Retrieved from https://www.thoughtco.com/definition-of-thiol-group-605735 Helmenstine, Anne Marie, Ph.D. "What Is a Thiol Group?" ThoughtCo. https://www.thoughtco.com/definition-of-thiol-group-605735 (accessed January 29, 2023). copy citation