cysteine
Noun
(amino acid) A sulphur-containing nonessential amino acid C3H7NO2S found in most animal proteins; it readily oxidizes to cystine.
Usage notes
When used as the name of a substance, this noun is uncountable, but when used as the name of individual molecules, it is countable.
Synonyms
* when used as a food additive
* when used as an improving agent
* Cys when viewed as a monomer in proteins
Not English
has no English definition. It may be misspelled.