Which statement about the relationship between an enzyme and the energetics of the reaction it catalyzes is correct?

Core Concept

Enzymes accelerate reactions by stabilizing the transition state, which lowers the activation energy barrier and increases the fraction of substrate molecules able to react at a given temperature. The free energy difference between substrate and product depends only on their chemical identities, so it is untouched by the catalyst. Consequently an enzyme speeds the forward and reverse directions equally and shifts neither the equilibrium position nor whether a reaction releases energy. It changes rate, never thermodynamic outcome.