Which of the following is a sulphur containing amino acid

Options

A. methionine
B. asparagine
C. serine
D. proline

Answer

To determine which of the following is a sulfur-containing amino acid, we will analyze each option provided:

1. **Identify the Options**: The options given are:
- Option A: Methionine
- Option B: Asparagine
- Option C: Serine
- Option D: Proline

2. **Analyze Each Option**:
- **Option A: Methionine**: Methionine is known to contain a sulfur atom in its side chain. Its structure includes a thioether group (-S-), which confirms that it is a sulfur-containing amino acid.
- **Option B: Asparagine**: Asparagine does not contain sulfur. Its side chain consists of an amide group (-CONH2) and does not include any sulfur atoms.
- **Option C: Serine**: Serine is another amino acid that does not contain sulfur. Its side chain is a hydroxymethyl group (-CH2OH).
- **Option D: Proline**: Proline also does not contain sulfur. Its structure includes a cyclic structure that does not have any sulfur atoms.

3. **Conclusion**: After analyzing all the options, we can conclude that the only amino acid that contains sulfur is **Option A: Methionine**.

### Final Answer:
The sulfur-containing amino acid is **Methionine** (Option A).