Definition of cysteine
: a crystalline sulfur-containing amino acid C3H7NO2S readily oxidizable to cystine
Recent Examples of cysteine from the Web
Eggs are an awesome source of cysteine, which helps break down a headache-causing toxin that's produced when your body digests alcohol.
Plants use sulfur to manufacture cysteine and methionine, two amino acids important for producing protein.
These example sentences are selected automatically from various online news sources to reflect current usage of the word 'cysteine'. Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
Origin and Etymology of cysteine
International Scientific Vocabulary, from cystine + -ein
First Known Use: 1884See Words from the same year
Medical Definition of cysteine
: a sulfur-containing amino acid C3H7NO2S occurring in many proteins and glutathione and readily oxidizable to cystine—abbreviation Cys
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