Which statement best describes enzyme function in catalysis?

• A. Enzymes increase the $E$_a of a reaction.
• B. Enzymes change the equilibrium position of a reaction.
• C. Enzymes are consumed in the reaction they catalyze.
• D. Enzymes provide an alternative reaction pathway with a lower $E$_a.

Answer: (D)

Verified step by step guidance

1. Understand the role of enzymes in catalysis: Enzymes are biological catalysts that speed up chemical reactions without being consumed in the process.
2. Recognize the concept of activation energy: Activation energy is the minimum energy required for a reaction to occur. Enzymes work by lowering this energy barrier.
3. Identify the effect of enzymes on reaction pathways: Enzymes provide an alternative pathway for the reaction, which has a lower activation energy compared to the uncatalyzed pathway.
4. Clarify the misconception about equilibrium: Enzymes do not change the equilibrium position of a reaction; they only affect the rate at which equilibrium is reached.
5. Conclude with the correct statement: The best description of enzyme function in catalysis is that enzymes provide an alternative reaction pathway with a lower activation energy.