cysteine
cysteine — noun
1. A type of amino acid — one of the molecules that form proteins — whose structure
A type of amino acid — one of the molecules that form proteins — whose structure includes a sulfur atom; two cysteine units can bond together to create the substance called cystine. It plays a role in building hair, nails, and skin, and in the body's antioxidant defenses.
Dr. Astrid explained how cysteine helps the body produce glutathione, a key antioxidant.
explain + how-clause showing biological function
Hair and nails get their strength from the high cysteine content of keratin proteins.
cysteine content of + [noun] — quantifying presence in a substance
After the surgery, Bao started eating more cysteine-rich foods such as eggs and chicken.
The lab technician measured the concentration of free cysteine in each blood sample.
In large proteins, cysteine molecules often form strong bonds that hold the overall shape together.
- Cys
Three-letter abbreviation used in biochemistry and protein notation, e.g. 'Cys25' refers to the cysteine residue at position 25
用法筆記
In biochemistry writing, 'cysteine' is usually treated as an uncountable noun when referring to it as a general substance (e.g. 'cysteine is found in hair'), but it may be countable when describing individual molecules or residues (e.g. 'three cysteines in the protein chain'). Do not confuse with cystine, which is the dimer formed when two cysteine molecules bond through their sulfur atoms.