The amino acid is coupled to the penultimate nucleotide at the 3 ' - end of the tRNA (the A in the sequence CCA) via an ester bond (roll over in illustration). The formation of the ester bond conserves a considerable part of the energy from the activation reaction. This stored energy provides the majority of the energy needed for peptide bond formation during translation.
where does the amino acid attach to trna
the penultimate nucleotide at the 3 ' - end of the tRNA