cysteine

noun

cys·​te·​ine ˈsi-stə-ˌēn 

: a crystalline sulfur-containing amino acid C₃H₇NO₂S readily oxidizable to cystine

Examples of cysteine in a Sentence

Recent Examples on the Web

Free radicals in tardigrades react with a protein called cysteine, the team discovered, but when those reactions are blocked, tardigrades can’t enter tun. —Carlyn Kranking, Smithsonian Magazine, 31 Dec. 2024

In the new study, the researchers combined cysteine with chemical relatives of fatty acids containing eight carbons apiece. —Bymitch Leslie, science.org, 30 Oct. 2024

To promote these reactions, alternative meat developers will add browning agents, including specific amino acids such as cysteine, methionine, and lysine, sugars, and the vitamin thiamin. —Discover Magazine, 28 Nov. 2024

The body naturally produces taurine from the amino acid cysteine. —Jillian Kubala, Rd, Health, 5 Nov. 2024

Word History

Etymology

International Scientific Vocabulary, from cystine + -ein

First Known Use

1884, in the meaning defined above

Medical Definition

cysteine

noun

cys·​teine ˈsis-tə-ˌēn 

: a sulfur-containing amino acid C₃H₇NO₂S occurring in many proteins and glutathione and readily oxidizable to cystine

—abbreviation Cys