In which of the following amino acids, R-group contains sulphur?

Options

A. Alanine
B. Serine
C. Threonine
D. Methionine

Answer

To solve the question "In which of the following amino acids, R-group contains sulphur?", we will analyze each option provided.

### Step-by-Step Solution:

1. **Understand the Question**: The question asks which amino acid has a side chain (R-group) that contains sulfur.

2. **Identify the Amino Acids**: We need to consider the common amino acids and their structures. The options provided are likely to include alanine, serine, threonine, and methionine.

3. **Analyze Each Option**:
- **Alanine**: The R-group of alanine is a methyl group (–CH3). This does not contain sulfur.
- **Serine**: The R-group of serine is a hydroxymethyl group (–CH2OH). This also does not contain sulfur.
- **Threonine**: The R-group of threonine is a hydroxyethyl group (–CH(OH)CH3). This does not contain sulfur either.
- **Methionine**: The R-group of methionine is an ethyl group with a thioether (–CH2CH2SCH3). This contains sulfur.

4. **Conclusion**: Among the options analyzed, methionine is the only amino acid that contains sulfur in its R-group.

5. **Final Answer**: The amino acid that contains sulfur in its R-group is **methionine**.