Final answer:
Peptide bond formation is catalyzed by a ribozyme component of the ribosomal RNA, known as peptidyl transferase, in both prokaryotes and eukaryotes. Option E.
Step-by-step explanation:
The formation of a peptide bond is a critical step in the synthesis of proteins. This process is catalyzed by an enzymatic component of the ribosome called peptidyl transferase.
It is interesting to note that peptidyl transferase is not a protein but part of the ribosomal RNA (rRNA), specifically the 23S rRNA in prokaryotes and the 28S rRNA in eukaryotes, thus making it a ribozyme.
Therefore, peptide bond formation is catalyzed by an RNA molecule in both prokaryotes and eukaryotes, making option E (both prokaryotes and eukaryotes) the correct answer.
In comparison to protein enzymes, ribozymes like peptidyl transferase utilize the chemical properties of RNA to catalyze reactions.
During the evolutionary transition from an RNA-only world to an RNA-protein world, RNAs such as peptidyl transferase would have been critical for the catalysis of peptide bond formation, ultimately leading to the synthesis of proteins that would take over many catalytic processes, including protein synthesis.
So Option E.