Science, Tech, Math › Science What Is a Thiol Group? Definition and Examples 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. 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 Read More Mercapto Group Definition By Anne Marie Helmenstine, Ph.D. 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 April 24, 2024). copy citation