University of Central Florida (UCF) BCH4024 Medical Biochemistry Practice Exam 1

The statement regarding whether enzymes can catalyze reactions that are away from equilibrium is nuanced and depends on what is meant by "away from equilibrium." Enzymes lower the activation energy of reactions, thus facilitating the conversion of substrates to products. However, they do not alter the position of equilibrium, meaning they cannot drive reactions to completion or change the ratio of products to reactants at equilibrium.

In biochemical terms, reactions are characterized by their equilibrium constants, which are determined by the free energy differences between reactants and products. While enzymes can speed up both the forward and reverse reactions, they do not change the thermodynamics of the reaction itself. Therefore, if a reaction is not at equilibrium, enzymes can still catalyze the reaction towards equilibrium but cannot take it to a state that is not defined by the equilibrium constant.

Thus, the claim is false because enzymes cannot catalyze reactions in a way that drives them away from their inherent equilibrium state. Instead, they facilitate the path toward reaching equilibrium more quickly.