Final answer:
Aminoacyl tRNA synthetases are responsible for adding the correct amino acid to the proper tRNA molecule.
Step-by-step explanation:
Aminoacyl tRNA synthetases are the enzymes that add the correct amino acid to the proper tRNA molecule. These enzymes are responsible for 'charging' the tRNA by catalyzing a bond between the tRNA and the corresponding amino acid. There is at least one type of aminoacyl tRNA synthetase for each of the 20 amino acids found in proteins.