cysteine

An alteration of cystine, see -eine.

• IPA^(key): /ˈsɪs.tɪ.iːn/

• Audio (Southern England):

  (file)

cysteine (countable and uncountable, plural cysteines)

1. (biochemistry) A sulphur-containing nonessential amino acid C₃H₇NO₂S found in most animal proteins; it readily oxidizes to cystine.

When used as the name of a substance, this noun is uncountable, but when used as the name of individual molecules, it is countable.

• E910 when used as a food additive
• E920 when used as an improving agent
• Cys when viewed as a monomer in proteins

• homocysteine