Science, Tech, Math › Science Definition of Zwitterion Print Bacsica / Getty Images 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 March 22, 2019 A zwitterion is a molecule that contains both positively and negatively charged functional groups, and the net charge of the entire molecule is zero. Amino acids are the best-known examples of zwitterions. They contain an amine group (basic) and a carboxyl group (acidic). Cite this Article Format mla apa chicago Your Citation Helmenstine, Anne Marie, Ph.D. "Definition of Zwitterion." ThoughtCo, Feb. 16, 2021, thoughtco.com/definition-of-zwitterion-604702. Helmenstine, Anne Marie, Ph.D. (2021, February 16). Definition of Zwitterion. Retrieved from https://www.thoughtco.com/definition-of-zwitterion-604702 Helmenstine, Anne Marie, Ph.D. "Definition of Zwitterion." ThoughtCo. https://www.thoughtco.com/definition-of-zwitterion-604702 (accessed April 19, 2024). copy citation