Which of the following is a non-polar amino acid?
(a) Alanine
(b) Glutamic acid
(c) Serine
(d) none of these

Options

A. Alanine
B. Glutamic acid
C. Serine
D. none of these

Answer

To determine which of the following is a non-polar amino acid, we need to analyze the options provided:

1. **Understanding Amino Acids**: Amino acids can be classified into polar and non-polar based on the nature of their side chains (R groups). Non-polar amino acids have side chains that do not interact favorably with water (hydrophobic), while polar amino acids have side chains that can interact with water (hydrophilic).

2. **Analyzing the Options**:
- **(a) Alanine**: Alanine has a side chain that is a simple methyl group (-CH3), making it non-polar.
- **(b) Glutamic acid**: Glutamic acid has a side chain that contains a carboxylic acid group (-COOH), which is polar.
- **(c) Serine**: Serine has a side chain that contains a hydroxyl group (-OH), which is also polar.
- **(d) None of these**: This option implies that none of the provided amino acids are non-polar.

3. **Conclusion**: Among the options, only alanine is classified as a non-polar amino acid.

Thus, the correct answer is **(a) Alanine**.