Side chain of which amino acid contains sulfhydryl group -

Ans. is 'b'' i.e., Cysteine o There are two sulfur containing amino acidsCysteineMethionineo The side chain of cysteine contains sulfhydryl group that has a pKa of approximately 8.4 for dissociation of its hydrogen sulfhydryl groups of two cvstein molecules can form covalent disulfide bond to form cystine,o Methionine although it contains sulfur group, does not containt sulfhydryl group and cannot form disulfide bond.