Question Detail
Question
Consider the following statements with reference to prokaryotic translation: 1. Charged tRNA carries amino acid at 5' end. 2. Charged tRNA enters the ribosome through A site during elongation of polypeptides. 3. Ribosomes can accommodate 3 mRNA codons at a time. 4. mRNA is translated from 5' > 3' direction. Which of the statements given above are correct?
Correct Answer
Option D is the correct answer.
Detailed Explanation
Statement 2 is correct: Charged tRNA (aminoacyl-tRNA) enters the ribosome at the A (aminoacyl) site during the elongation phase. Statement 4 is correct: mRNA is translated in the 5' to 3' direction. Statement 1 is incorrect: Charged tRNA carries the amino acid at the 3' end (the CCA tail), not the 5' end. Statement 3 is incorrect: A ribosome can accommodate two codons at a time (one at the A site and one at the P site), not three.
Hint
Recall the mechanics of translation, including tRNA charging, ribosome sites, and directionality.