Disulfide bonds are formed in which amino acid:

Ans. (b) Cysteine* -SH group of 2 cysteine in proteins can be oxidized to form a covalent disulfide bond.* It significantly stabilizes tertiary structures of protein* This bond plays crucial role in structures of many proteins by forming covalent links.* Amino acid that decreases ageing process: Cysteine and Taurine* Amino acid that accelerate ageing: Homocysteine