This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Enzymes catalysing the synthetic reactions where two molecules are joined together and ATP is used; belongs to which class? 
Select and explain. 
A. Hydrolase, B. Lyase, C. Ligase, D. Transferase
C: Ligase
Answer: C: Ligase 
Explanation: Oxidoreductases: Enzymes involved in oxidation-reduction reactions.
Transferases: Enzymes that catalyse the transfer of functional groups.
Hydrolases: Enzymes that bring about hydrolysis of various compounds.
Lyases: Enzymes specialized in the addition or removal of water, ammonia, CO2 etc.
Isomerases: Enzymes involved in all the isomerization reactions.
Ligases: Enzymes catalysing the synthetic reactions (Greek: ligate-to bind) where two molecules are joined together and ATP is used.

Reference - satyanarayana Pg-87