This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
[{'content': 'Which of the following functionally competent of largest unit of the ribosomes? \nSelect and explain. \nA. tRNA, B. mRNA, C. Catalyze formation of the peptides, D. Formation of the polyribosomes', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ribosomes catalyze peptide bond formation between aminoacyl- tRNA (aa-tRNA)4 bound to the A site of the ribosome and peptidyl- tRNA at the P site.The active site for peptide bond formation, the peptidyl transferase center, is located on the large (50 S) ribosomal subunit. High-resolution crystal structures of the 50 S subunit have revealed that the peptidyl transferase center is composed of RNA (23 S rRNA), with no protein within 15 A of the active site (1, 2).This implies that peptide bond formation is catalyzed by RNA and, thus, the ribosome is a ribozyme.', 'role': 'assistant'}]