The initiating codon AUG specifies for

Options

A. valine
B. leucine
C. lysine
D. methionine

Answer

To answer the question "The initiating codon AUG specifies for," we will analyze the given options and identify which amino acid is encoded by the codon AUG.

### Step-by-Step Solution:

1. **Identify the Codon**: The question asks about the codon AUG. This codon is known as the start codon in the genetic code.

2. **Research the Amino Acids**: We need to determine which amino acid is specified by the codon AUG. The options given are:
- Valine
- Leucine
- Lysine
- Methionine

3. **Check Each Option**:
- **Valine**: Valine is encoded by the codons GUU, GUC, GUA, and GUG. Therefore, AUG does not specify valine.
- **Leucine**: Leucine is encoded by the codons UUA, UUG, CUU, CUC, CUA, and CUG. Therefore, AUG does not specify leucine.
- **Lysine**: Lysine is encoded by the codons AAA and AAG. Therefore, AUG does not specify lysine.
- **Methionine**: Methionine is specifically encoded by the codon AUG. This means that AUG does indeed specify methionine.

4. **Conclusion**: Since AUG is the start codon and it encodes for methionine, the correct answer to the question is:
- **Methionine**

### Final Answer:
The initiating codon AUG specifies for **Methionine**.

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