What happens to enzymes after the reaction they catalyze is complete?

• A. They are consumed in the reaction and need to be replenished.
• B. They become inactive and require activation for reuse.
• C. They are permanently altered and cannot be reused.
• D. They are released unchanged and can catalyze further reactions.

Answer: (D)

Verified step by step guidance

1. Understand the role of enzymes: Enzymes are biological catalysts that speed up chemical reactions without being consumed in the process.
2. Recognize the nature of enzyme action: Enzymes lower the activation energy of a reaction, allowing it to proceed more quickly, but they do not undergo permanent changes themselves.
3. Consider the enzyme's structure: Enzymes have an active site where substrates bind. This site is specific to the substrate and facilitates the conversion to products.
4. After the reaction, the enzyme releases the product and remains unchanged, ready to catalyze another reaction with a new substrate molecule.
5. Conclude that enzymes are not consumed or permanently altered during the reaction, allowing them to be reused multiple times for catalyzing similar reactions.