This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Structure and function of protein, Subject name: Biochemistry
Disulphide bond is seen between 
Select and explain. 
A. Arginine and histidine, B. Arginine and cysteine, C. Cysteine and cysteine, D. Lysine and cysteine
C: Cysteine and cysteine
Answer: C: Cysteine and cysteine 
Explanation: Disulphide bonds: These are formed between two cysteine residues. They are strong, high energy covalent bonds.Ref: Textbook of medical biochemistry, MN Chatterji, 8th edition, page no: 89