Answer:
Insulin catalyzes the anabolic reaction.
Explanation:
Insulin and glucagon, while both are produced in the pancreas and regulate glucose concentration in blood, have opposite effects.
An anabolic reaction consists of uniting smaller molecules in order to form bigger ones. Insulin, in this case, sends a signal to stimulate the processes of glycogenesis and lipogenesis (both using glucose as a substrate to make bigger molecules).
Glucagon, on the contrary, catalyzes catabolic reactions: breaking glycogen molecules to obtain glucose (this process is called glycogenolysis).