Final answer:
The aminoacyl group at the 3' end of the tRNA is vital for concerted proton transfer, allowing the formation of peptide bonds by the action of peptidyl transferase during protein synthesis.
Step-by-step explanation:
In the context of protein synthesis, the group of the tRNA that is critical for concerted proton transfer is the aminoacyl group present at the 3' end of the tRNA molecule. This aminoacyl group is where the amino acid is attached, and during peptide bond formation, the amino group of the amino acid bound to the A-site tRNA reacts with the carboxyl group of the amino acid bound to the P-site tRNA.
This reaction is facilitated by the ribozyme peptidyl transferase, which is a critical component of the ribosomal subunit. The activity of peptidyl transferase ensures the proper formation of peptide bonds, a process that consumes considerable energy, utilizing GTP hydrolysis to catalyze both the binding and positioning of tRNA in the ribosomal sites (A, P, and E sites) as well as the peptide bond formation during protein elongation.