Final answer:
The energy for binding of the next tRNA to the A site during elongation in prokaryotic cells comes from the hydrolysis of GTP, a process assisted by elongation factors.
Step-by-step explanation:
The energy for the binding of the next tRNA to the A site during elongation in prokaryotic cells is provided by the hydrolysis of guanosine triphosphate (GTP).
This process is facilitated by elongation factors.
The specific elongation factor that carries the charged tRNA to the A site is known as EF-Tu in prokaryotes.
EF-Tu, bound to GTP, forms a complex with the charged aminoacyl-tRNA.
Upon successful binding of the aminoacyl-tRNA to the codon in the A site, GTP is hydrolyzed to GDP and inorganic phosphate (Pi), providing the necessary energy for the precise positioning of the tRNA and the subsequent peptide bond formation which will occur between the amino acid at the A site and the growing polypeptide chain at the P site.