In the context of biological systems, why are enzymes crucial for chemical reactions?

• A. Enzymes decrease the $E$_a, speeding up reactions.
• B. Enzymes are consumed in the reactions they catalyze.
• C. Enzymes increase the $E$_a required for reactions.
• D. Enzymes change the equilibrium position of reactions.

Answer: (A)

Verified step by step guidance

1. Understand the role of enzymes: Enzymes are biological catalysts that speed up chemical reactions in biological systems without being consumed in the process.
2. Identify the effect of enzymes on activation energy: Enzymes work by lowering the activation energy required for a reaction to proceed, making it easier for the reaction to occur.
3. Clarify the misconception about enzyme consumption: Enzymes are not consumed in the reactions they catalyze; they remain unchanged and can be used repeatedly.
4. Examine the impact on reaction equilibrium: Enzymes do not change the equilibrium position of a reaction; they only speed up the rate at which equilibrium is reached.
5. Summarize the key points: Enzymes are crucial because they lower activation energy, increase reaction rates, and are not consumed, without altering the equilibrium position.