Final answer:
Peptidyl transferase is the ribozyme responsible for peptide bond formation in protein synthesis, located in the 50S ribosomal subunit. It catalyzes the condensation reaction during the elongation phase, contributing to the growth of the polypeptide chain, and highlights the catalytic potential of rRNA within the ribosome.
Step-by-step explanation:
The ribozyme responsible for peptide bond formation in protein synthesis is peptidyl transferase. This RNA-based enzyme is an integral part of the 50S ribosomal subunit and plays a crucial role during the elongation phase of protein synthesis. Specifically, peptidyl transferase facilitates the condensation reaction, where it catalyzes the peptide linkage between the amino group of the incoming amino acid in the A site and the carboxylate group of the terminal amino acid on the tRNA located at the P site. As a result, the newly formed peptide chain grows sequentially with the addition of each amino acid.
The activity of peptidyl transferase is a prime example of a ribozyme, showcasing the catalytic capabilities of RNA. The discovery of this enzymatic function of rRNA within the ribosome significantly advanced our understanding of the molecular basis of protein synthesis.
Notably, findings such as these contributed to the awarding of the Nobel Prize in Chemistry to scientists including Thomas Steitz, who helped elucidate the structural and catalytic nature of the ribosome. This discovery underscored the ribosome's role as a molecular machine that not only aligns mRNA, tRNA, and ribosomal subunits but also catalyzes the critical chemical reactions necessary for the formation of functional proteins.