Question

In protein synthesis, during elongation of a polypeptide chain, the charged tRNA carrying the aminoacid is received at ___ site and uncharged tRNA is released from ___ site of the ribosome respectively.

• A. 'A' and 'P'
• B. 'P' and 'A'
• C. 'A' and 'E'
• D. 'P' and 'E'

Hint:

Charged tRNA enters the A site and the empty tRNA leaves from the E site.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept
A ribosome has three tRNA binding sites: A (aminoacyl), P (peptidyl) and E (exit).

Step 2: Elongation steps
A new charged tRNA whose anticodon matches the codon enters the A site.
After peptide bond formation the ribosome shifts one codon, and the uncharged tRNA moves to the E site and is released.

Step 3: Conclusion
So the charged tRNA is received at the A site and the uncharged tRNA is released from the E site.

Final Answer:
The sites are A and E respectively. \[ \boxed{\text{(C) }\text{'A' and 'E'}} \]