Transfer
of
Amino
Acids
to
tRNA - The transfer of the activated amino acid to tRNA (charging of tRNA), is also specific. About 100 different types of tRNA are found in each cell. The tRNA is named after the amino acid for which it is specific. Thus the tRNAs for the amino acids isoleucine and valine are designated as tRNA ileu and tRNA val, respectively.
The activated amino acid is transferred to its specific tRNA. A high energy ester bond is formed between the carboxyl group of the amino acid and the 3'-hydroxy group of the terminal adenosine of tRNA. The aminoacyl adenylate, which is attached to the activating enzyme (synthetase), reacts with a specific tRNA to form an aminoacyl tRNA complex.
