Polypeptide chain in eukaryotes is initiated by codons coding for amino acid

Options

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

Answer

To solve the question regarding the initiation of the polypeptide chain in eukaryotes, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Codons**:
- Codons are sequences of three nucleotides in mRNA that correspond to specific amino acids. In total, there are 64 possible codons.

2. **Identifying Start Codon**:
- Among these codons, one specific codon, AUG, serves a dual purpose: it codes for the amino acid methionine and acts as the start codon for protein synthesis.

3. **Role of AUG**:
- The AUG codon is recognized by the ribosome as the starting point for translation. When the ribosome encounters this codon, it begins assembling the amino acids into a polypeptide chain.

4. **First Amino Acid**:
- Since AUG codes for methionine, the first amino acid in the newly synthesized polypeptide chain will always be methionine.

5. **Conclusion**:
- Therefore, the polypeptide chain in eukaryotes is initiated by the codon that codes for methionine.

### Final Answer:
The polypeptide chain in eukaryotes is initiated by the codon coding for the amino acid **methionine**.

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