Cysteine is abundantly found in:
High-Yield Explanation
Ans: a (Keratin) Ref:Vasudevan, 4th ed, p.178; 5th ed, p. 191Cysteine is found in large quantities in keratin of hair and nails.Products of amino acids:TyrosineThyroid hormonesMelaninCatecholaminesThvptophanSerotoninMelatoninNADNADPArginineNitri oxideGlutamateGABAHistidineHistanineFIGLUOrnithine + methionineSpermineSpermidineGlycine+Arginine + MethionineCreatinine