Select the incorrect statement about translation

Options

A. An mRNA has some additional sequence that are not translation and are referred to as untranslated region (UTR).
B. The ribosome acts as a catalyst (23S rRNA in bacteria is the enzyme -ribozyme) for the formation of a peptide bond.
C. The ribosome consists of structural RNAs and about 60 different proteins.
D. For initiation, the ribosome binds to the mRNA at the start codon (AUG) that is recognised only by the initiator tRNA

Answer

To solve the question of identifying the incorrect statement about translation, we will analyze each statement provided in the question step by step.

### Step-by-Step Solution:

1. **Statement Analysis**:
- **Statement 1**: "An mRNA has some additional sequences that are not translated and these sequences are referred to as untranslated regions or UTRs."
- **Analysis**: This statement is correct. mRNA indeed has untranslated regions (UTRs) at both the 5' and 3' ends which do not code for proteins.

2. **Statement 2**: "The ribosome acts as a catalyst 23S rRNA in bacteria and the enzyme is ribozyme for the formation of peptide bond."
- **Analysis**: This statement is also correct. The 23S rRNA in the ribosome acts as a ribozyme, facilitating the formation of peptide bonds between amino acids.

3. **Statement 3**: "The ribosome consists of structural RNAs and about 60 different proteins."
- **Analysis**: This statement is incorrect. The ribosome is composed of structural RNAs and approximately 80 different proteins, not 60.

4. **Statement 4**: "For initiation, the ribosome binds to the mRNA at the start codon AUG that is recognized only by the initiator tRNA."
- **Analysis**: This statement is correct. The ribosome binds to the start codon AUG, which is recognized by the initiator tRNA carrying methionine.

### Conclusion:
The incorrect statement about translation is **Statement 3**: "The ribosome consists of structural RNAs and about 60 different proteins."

### Final Answer:
The answer to the question is **Option 3**.

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