Final answer:
A ribozyme catalyzes the formation of peptide bonds in the process of protein synthesis, which is the correct answer to the student's question.
Step-by-step explanation:
The biochemical reaction that is catalyzed by a ribozyme is the peptide bond formation in protein synthesis. This enzymatic activity is attributed to the ribosomal RNA (rRNA) within the ribosome, particularly the peptidyl transferase component, which catalyzes the condensation reaction during protein synthesis. The process involves the ribosome catalyzing the peptide bond formation between the amino group of an incoming amino acid and the carboxylate group of the nascent polypeptide chain. Specifically, this occurs in the ribosome's large subunit, which contains the active site known as the peptidyl transferase center (PTC), responsible for this catalysis. Hence, the correct answer is A. peptide bond formation in protein synthesis.