In an antibody molecule antigen binding site is present at.

Options

A. Light chains
B. Heavy chains
C. Both heavy and light chains
D. None of these

Answer

**Step-by-Step Solution:**

1. **Understanding Antibody Structure**: Antibodies, also known as immunoglobulins, are Y-shaped molecules composed of four polypeptide chains: two heavy chains and two light chains.

2. **Identifying the Antigen Binding Site**: The antigen binding site is the region of the antibody that specifically binds to an antigen. This site is formed by the variable regions of both the heavy and light chains.

3. **Locating the Binding Site**: The antigen binding site is located at the tips of the Y-shaped structure of the antibody. It is formed by the combination of the variable regions of the heavy and light chains.

4. **Conclusion**: Therefore, the antigen binding site is present at both the heavy and light chains of the antibody molecule.

5. **Final Answer**: The correct option is that the antigen binding site is present at both the heavy and light chains.

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