 Aminoacyl @-@ tRNA synthetase enzymes utilize ATP as an energy source to attach a tRNA molecule to its specific amino acid , forming an aminoacyl @-@ tRNA complex , ready for translation at ribosomes . The energy is made available by ATP hydrolysis to adenosine monophosphate ( AMP ) as two phosphate groups are removed . Amino acid activation refers to the attachment of an amino acid to its Transfer RNA ( tRNA ) . Aminoacyl transferase binds Adenosine triphosphate ( ATP ) to amino acid , PP is released . Aminoacyl transferase binds AMP @-@ amino acid to tRNA . The AMP is used in this step . 
