Which of the following inhibits binding of amino-acyl tRNA to ribosomes?

Options

A. Necomycin
B. Erthromycin
C. Streptomycin
D. tetracyclin

Answer

To solve the question "Which of the following inhibits binding of amino-acyl tRNA to ribosomes?" let's analyze each of the options provided:

1. **Neomycin**: This antibiotic binds to the 30S subunit of the ribosome. While it affects protein synthesis, it does not specifically inhibit the binding of amino-acyl tRNA to the ribosome.

2. **Erythromycin**: This antibiotic binds to the 50S subunit of the ribosome, specifically to the 23S rRNA. It primarily inhibits the translocation step during protein synthesis but does not directly inhibit the binding of amino-acyl tRNA.

3. **Streptomycin**: This antibiotic also binds to the 30S subunit, specifically to the 16S rRNA. Like neomycin, it affects protein synthesis but does not directly inhibit the binding of amino-acyl tRNA.

4. **Tetracycline**: This antibiotic specifically inhibits the binding of incoming amino-acyl tRNA to the ribosome. It prevents the attachment of tRNA to the ribosome, thus directly affecting the translation process.

Based on the analysis above, the correct answer to the question is **Tetracycline**.

### Step-by-Step Solution:
1. **Identify the question**: Determine which antibiotic inhibits the binding of amino-acyl tRNA to ribosomes.
2. **Analyze each option**:
- Neomycin: Binds to 30S subunit but does not inhibit tRNA binding.
- Erythromycin: Binds to 50S subunit but does not inhibit tRNA binding.
- Streptomycin: Binds to 30S subunit but does not inhibit tRNA binding.
- Tetracycline: Specifically inhibits the binding of amino-acyl tRNA.
3. **Select the correct answer**: Based on the analysis, Tetracycline is the antibiotic that inhibits the binding of amino-acyl tRNA to ribosomes.