The class of enzymes that catalyzes synthetic reactions where two molecules are joined together and ATP is used is HomeEnzymology MCQsThe class of enzymes that catalyzes synthetic reactions where two molecules are joined together and ATP is used is Q. The class of enzymes that catalyzes synthetic reactions where two molecules are joined together and ATP is used is A. Hydrolases B. Lyases C. Ligases D. Isomerases Answer: Ligases