Answer:
The initial step in the formation of an aminoacyl-tRNA is activation of the amino acid by reaction with ATP
Explanation:
In protein synthesis, the first step involves the formation of an aminoacyl-tRNA. This reaction is catalyzed by the the Mg²⁺-dependent enzymes known as aminoacyl t-RNA synthetases and occurs in two steps.
The first step of the reaction of the formation of an aminoacyl-tRNA is the activation of the amino acid by the attachment of an AMP molecule formed from the hydrolysis of ATP to AMP and pyrophosphate. The aminoacyl adenylate intermediate is bound to the enzyme in this initial step. Subsequently, in the second step of the activation of the amino acid, the aminoacyl adenylate intermediate is then transferred to its specific tRNA. The pyrophosphate formed in the first step is hydrolyzed to 2 phosphate molecules by a pyrophosphatase.
The overall reaction step is illustrated below:
Amino acid + tRNA + ATP -----> aminoacyl-tRNA +AMP + 2Pi
