Select the aromatic amino acids : (a) Tyrosine (b) Valine (c ) Lysine (d) Tryptophan (e ) Serine.

Options

A. a and d only
B. a, d and e
C. c and d only
D. b and d only.

Answer

To solve the question of selecting the aromatic amino acids from the given options, we will follow these steps:

### Step 1: Understand Aromatic Amino Acids
Aromatic amino acids are those that contain an aromatic ring in their structure. The most common aromatic amino acids include tyrosine, tryptophan, and phenylalanine.

### Step 2: Analyze Each Option
Now, let's analyze each of the provided options to determine if they are aromatic:

- **(a) Tyrosine**: This amino acid contains a phenolic ring, which is aromatic. Therefore, tyrosine is an aromatic amino acid.

- **(b) Valine**: This is a branched-chain amino acid and does not contain an aromatic ring. Hence, valine is not an aromatic amino acid.

- **(c) Lysine**: This amino acid has a long aliphatic side chain and does not contain an aromatic ring. Therefore, lysine is not an aromatic amino acid.

- **(d) Tryptophan**: This amino acid contains an indole ring, which is aromatic. Thus, tryptophan is an aromatic amino acid.

- **(e) Serine**: This amino acid has a hydroxyl group in its side chain but does not contain an aromatic ring. Therefore, serine is not an aromatic amino acid.

### Step 3: Conclusion
After analyzing all the options, we find that the aromatic amino acids from the list are:
- Tyrosine (a)
- Tryptophan (d)

Thus, the correct answer is (a) Tyrosine and (d) Tryptophan.

### Final Answer:
The aromatic amino acids are: **(a) Tyrosine and (d) Tryptophan.**

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