Aminoacyl-tRNAs are synthesized in two steps: 

1. The first step involves ATP (Adenosine Triphosphate) - dependent adenylation of the amino acid, resulting in the formation of aminoacyl-AMP (Adenosine Monophosphate).

The net reaction in this step is: ATP + Amino acid = Aminoacyl-AMP + PPi(Pyrophosphate)

2. In the second step, the amino acid residue is transferred to the tRNA (Transfer RNA).

The net reaction in this step is: ATP + Amino Acid + tRNA = Aminoacyl-tRNA + AMP + PPi