methionine

noun

me·​thi·​o·​nine mə-ˈthī-ə-ˌnēn 

: a crystalline sulfur-containing essential amino acid C₅H₁₁NO₂S that occurs in the levorotatory form as a constituent of many proteins

Examples of methionine in a Sentence

Recent Examples on the Web

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

It is made up of three main amino acids—glycine, arginine, and methionine. —Jillian Kubala, Health, 12 Aug. 2024

What is Creatine? Creatine is made from three amino acids: glycine, arginine, and methionine. —Staff Author, Health, 6 Aug. 2024

Your body makes creatine from three amino acids: arginine, glycine, and methionine. —Elizabeth Barnes, Verywell Health, 6 Aug. 2024

Word History

Etymology

International Scientific Vocabulary, from methyl + thion- + -ine entry 2

First Known Use

1928, in the meaning defined above

Medical Definition

methionine

noun

me·​thi·​o·​nine mə-ˈthī-ə-ˌnēn 

: a crystalline sulfur-containing essential amino acid C₅H₁₁NO₂S that occurs in the L-form as a constituent of many proteins (as casein and egg albumin), that is important especially as a source of sulfur for the biosynthesis of cysteine and as a source of methyl groups for transmethylation reactions (as in the biosynthesis of choline, creatine, and adrenaline), and that is used as a dietary supplement for human beings and their domestic mammals and poultry and in the treatment of fatty infiltration of the liver

—abbreviation Met