• Cysteine

    Origin

    An alteration of cystine.

    Full definition of cysteine

    Noun

    cysteine

    (countable and uncountable; plural cysteines)
    1. (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

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