Question

How is ATP used to charge a tRNA?

Short answer

The ATP is used to activate the inactive amino acid, which then reacts with the tRNA and attaches the aminoacyl with the tRNA (aa-tRNA). The aa-tRNA is a compound with high energy, which is why the tRNA is termed as charged.

Step-by-step solution

Activation of Amino acid

Inactivated amino acid and ATP bind with the help of an enzyme. The enzyme catalyzes the coupling of amino acid to AMP which gives aminoacyl-AMP or known as aminoacyl-adenylate. As byproducts, two phosphates are lost.

tRNA charged

The activated aminoacyl-AMP then reacts with tRNA and forms aminoacyl-tRNA (aa-tRNA)

Aminoacyl-AMP + tRNA aa-tRNA + AMP

The aa-tRNA is the compound of high energy, associated with the amino acids termed as activated and tRNA termed as charged.