The dipeptide glyclalanine contains

Options

A. glycine as C-terminal residue
B. glycine as N - terminal residue
C. alanine as N - terminal residue
D. either (1) or (2)

Answer

To determine the components of the dipeptide glycylalanine, we need to analyze its structure and the amino acids involved.

### Step-by-Step Solution:

1. **Identify the Amino Acids**:
- The dipeptide glycylalanine is composed of two amino acids: glycine and alanine.

2. **Understand the Structure of Amino Acids**:
- Glycine (Gly) has the structure: NH2-CH2-COOH.
- Alanine (Ala) has the structure: NH2-CH(CH3)-COOH.

3. **Determine the N-terminal and C-terminal**:
- In a dipeptide, the N-terminal is the end with the free amino group (NH2), and the C-terminal is the end with the free carboxyl group (COOH).
- For glycylalanine, glycine will be at the N-terminal position because it is the first amino acid in the sequence.
- Alanine will be at the C-terminal position because it is the second amino acid in the sequence.

4. **Conclusion**:
- Therefore, glycylalanine contains glycine as the N-terminal residue and alanine as the C-terminal residue.

### Final Answer:
The dipeptide glycylalanine contains glycine as the N-terminal residue and alanine as the C-terminal residue.

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