Starting codon in prokaryotes codes for

Options

A. methyl methionine
B. ethyl methionine
C. propyle methionine
D. formyl methionine

Answer

To answer the question about what the starting codon in prokaryotes codes for, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Codons**: Codons are sequences of three nucleotides that correspond to specific amino acids or signals during protein synthesis.

2. **Identifying the Start Codon**: In both prokaryotes and eukaryotes, the process of translation begins with a start codon. The most common start codon is AUG, which codes for the amino acid methionine in eukaryotes.

3. **Prokaryotic Start Codon**: In prokaryotes, the start codon also begins with AUG, but it codes for a modified form of methionine known as N-formylmethionine (fMet).

4. **Role of fMet-tRNA**: The fMet-tRNA (transfer RNA) is specifically used in prokaryotes to initiate protein synthesis. It carries the N-formylmethionine to the ribosome, where translation begins.

5. **Conclusion**: Therefore, the starting codon in prokaryotes codes for N-formylmethionine (fMet).

### Final Answer:
The starting codon in prokaryotes codes for N-formylmethionine (fMet).

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