Serine is coded by a letter

Options

A. S
B. C
C. Y
D. E

Answer

To determine which letter codes for the amino acid serine, we can follow these steps:

1. **Identify the Amino Acid**: We need to find the one-letter code for the amino acid serine.

2. **Review the Options**: The options given are:
- A) S
- B) C
- C) Y
- D) E

3. **Recall the One-Letter Codes**:
- Serine is known to be represented by the letter 'S'.
- Cysteine is represented by 'C'.
- Tyrosine is represented by 'Y'.
- Glutamic acid is represented by 'E'.

4. **Select the Correct Option**: Based on the one-letter codes, the letter that corresponds to serine is 'S'.

5. **Conclusion**: Therefore, the correct answer is option A, which is 'S'.