Question

In an antibody, disulphide bonds are present________
i. between two heavy chains
ii. between two light chains
iii. between the constant region of light chain and the constant region of a heavy chain
iv. between antigen binding sites of both the heavy and light chains
v. between the variable region of light chain and that of heavy chain
Select the correct answer from the options given below

• A. i and ii only
• B. i and iii only
• C. ii and v only
• D. ii and iv only

Hint:

Antibody structure: Heavy--Heavy bond + Heavy--Light bond (via disulphide)

Answer 1

The Correct Option is B

Concept: Antibodies (immunoglobulins) are Y-shaped proteins made of two heavy chains and two light chains.
• Chains are linked by disulphide bonds.
• These bonds maintain structural stability.

Step 1: Understand structure.

• Two heavy chains are linked by disulphide bonds
• Each light chain is attached to a heavy chain via disulphide bond

Step 2: Evaluate statements.
• (i) Between two heavy chains: Correct
• (ii) Between two light chains: Incorrect
• (iii) Between constant region of light and heavy chain: Correct
• (iv) Between antigen binding sites: Incorrect
• (v) Between variable regions: Incorrect

Step 3: Conclusion.
Correct statements are i and iii. Final Answer: Option (B)