A ribosome with three tRNA-binding sites (E, P, A) is shown translating an mRNA in the 5' to 3' direction.
During elongation, where is the next amino-acid-charged tRNA delivered, and where does the peptide bond form?
- A
Charged tRNA enters the A site; peptide bonds form between adjacent ribosomal subunits.
- Bcheck_circle
Charged tRNA enters the A site; peptide bond forms between the A-site amino acid and the polypeptide on the P-site tRNA.
- C
Charged tRNA enters the E site; peptide bond forms in the P site.
- D
Charged tRNA enters the P site; peptide bond forms in the E site.
Explanation
The aminoacyl (A) site receives the incoming charged tRNA; peptidyl transferase activity (in the large subunit rRNA) catalyzes peptide-bond formation between the A-site amino acid and the polypeptide on the P-site tRNA.