This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Proteins and Amino Acids, Subject name: Biochemistry
[{'content': 'Disulfide bonds are formed in which amino acid: \nSelect and explain. \nA. Glycine, B. Cysteine, C. Proline, D. Isoleucine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: 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', 'role': 'assistant'}]