This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Translation, Subject name: Biochemistry
The hydrolytic step leading to the release of a polypeptide chain from a ribosome is catalyzed by which of the following? 
Select and explain. 
A. Dissociation of ribosomes, B. Peptidyl transferase, C. Release factors, D. Stop codons
B: Peptidyl transferase
Answer: B: Peptidyl transferase 
Explanation: Peptidyl transferase is responsible for the release of peptidyl chain from a ribosome The release is not done by releasing factor, During termination of translation we have releasing factors: In prokaryotes - RF 1 2 3 Eukaryotes - eRF Releasing factor (misnomer) - it can only recognize the stop codon Hence, The hydrolytic step leading to the release of a polypeptide chain from a ribosome is catalyzed by Peptidyl transferase (not by releasing factors).