Final answer:
The 28S rRNA is responsible for the peptidyl transferase reaction during translation, which is crucial for the formation of peptide bonds in the growing polypeptide chain.
Step-by-step explanation:
The rRNA responsible for the peptidyl transferase reaction during translation is 28S rRNA. This reaction is catalytic activity that occurs in the large subunit of the ribosome, where the 28S rRNA is located. This enzyme is vital for the formation of peptide bonds between amino acids as they are added to the growing polypeptide chain during protein synthesis.