What is unusual about the protein sequence 'VDAATAEKVFKQY'?

• A. It contains only hydrophobic amino acids.
• B. It contains a disulfide bond.
• C. It lacks any aromatic amino acids.
• D. It is composed entirely of essential amino acids.

Answer: (C)

Verified step by step guidance

1. Step 1: Begin by analyzing the given protein sequence 'VDAATAEKVFKQY'. Identify the amino acids present in the sequence by their single-letter codes.
2. Step 2: Recall the classification of amino acids. Aromatic amino acids include phenylalanine (F), tyrosine (Y), and tryptophan (W). Check if any of these are present in the sequence.
3. Step 3: Hydrophobic amino acids include alanine (A), valine (V), leucine (L), isoleucine (I), methionine (M), phenylalanine (F), and tryptophan (W). Verify if the sequence contains only hydrophobic amino acids.
4. Step 4: Disulfide bonds are formed between cysteine (C) residues. Check if the sequence contains cysteine, which is necessary for disulfide bond formation.
5. Step 5: Essential amino acids include histidine (H), isoleucine (I), leucine (L), lysine (K), methionine (M), phenylalanine (F), threonine (T), tryptophan (W), and valine (V). Determine if the sequence is composed entirely of these essential amino acids.