Final answer:
Aminoacyl-tRNA synthetases have an activation site and an editing site. They catalyze the attachment of amino acids to their respective tRNA molecules, a critical step in protein synthesis.
Step-by-step explanation:
Aminoacyl-tRNA synthetases are crucial enzymes in the process of protein synthesis. These enzymes have two primary sites: an activation site, where the enzyme binds and hydrolyzes ATP to catalyze a high-energy bond between an amino acid and adenosine monophosphate (AMP), and an editing site.
The activated amino acid is then transferred to a tRNA molecule, thereby "charging" the tRNA, and making it ready for participation in protein synthesis at the ribosome.