How does an enzyme influence a chemical reaction?

• A. It changes the reaction's overall free energy change ($\Delta G$) so the reaction becomes thermodynamically favorable even if it was unfavorable before.
• B. It lowers the activation energy by stabilizing the transition state, increasing the reaction rate without changing the overall free energy change ($\Delta G$) or equilibrium constant.
• C. It shifts the equilibrium constant by binding substrates and permanently converting them into products.
• D. It increases the activation energy so that the reaction proceeds more slowly and produces more product at equilibrium.

Answer: (B)

Verified step by step guidance

1. Understand that enzymes are biological catalysts that speed up chemical reactions without being consumed in the process.
2. Recall that the overall free energy change of a reaction, denoted as \(\Delta\Delta G\), determines whether a reaction is thermodynamically favorable or not, and enzymes do not alter this value.
3. Recognize that enzymes work by lowering the activation energy (\(E_a\)), which is the energy barrier that must be overcome for reactants to be converted into products.
4. Know that enzymes stabilize the transition state of the reaction, making it easier for the reaction to proceed and thus increasing the reaction rate.
5. Conclude that while enzymes increase the speed at which equilibrium is reached, they do not change the equilibrium constant or the overall free energy change of the reaction.