Final answer:
The peptidyl transferase acts as a catalyst to hydrolyze the peptide chain from the tRNA carrier in response to release factors and nonsense codons during translation termination.
Step-by-step explanation:
The presence of release factors (RFs) with a nonsense codon at the A site of the ribosome transforms the peptidyl transferase into a catalytic entity which cleaves the peptidyl chain from the tRNA carrier. This action is crucial for the termination of translation when a nonsense codon (UAA, UAG, or UGA) is encountered.
During this process, the release factors instruct the peptidyl transferase to add a water molecule to the carboxyl end of the P-site amino acid. Consequently, the peptide chain is hydrolyzed, which results in its release from the tRNA. This marks the end of protein synthesis, as the ribosomal subunits dissociate and become available for another round of translation.