Question

The initiator tRNA attaches at the ribosome's _____ site.

1) A
2) translocation
3) E
4) P
5) Q

Answer 1

The initiator tRNA binds to the P site of the ribosome during the initiation phase of protein synthesis.

Step-by-step explanation:

The initiator tRNA attaches at the ribosome's P site. During the initiation phase of protein synthesis, the initiator tRNA carrying methionine encounters the AUG start codon specifically at the P-site of the ribosome. As translation proceeds into the elongation phase, the amino acids on tRNA in the P-site bond with amino acids on tRNA in the A-site. After a peptide bond forms, the ribosome undergoes a process known as translocation, where it moves along the mRNA, and the tRNA shifts from the A-site to the P-site and then to the E-site for exit.