Which of the following are unique features about the enzyme?

Options

A. They are not consumed by the enzyme-mediated reaction
B. They are not altered by the enzyme-mediated reaction
C. They lower the activation energy
D. All

Answer

**Step-by-Step Solution:**

1. **Understanding Enzymes:**
Enzymes are biological catalysts that speed up chemical reactions in living organisms. They are typically proteins that facilitate various biochemical processes.

2. **Enzyme-Substrate Interaction:**
When a substrate (the molecule upon which an enzyme acts) binds to the enzyme, it fits into a specific region called the active site. This binding alters the shape of the enzyme slightly, allowing for a better fit around the substrate.

3. **Formation of Enzyme-Substrate Complex:**
Once the substrate is bound, an enzyme-substrate complex is formed. This complex is usually short-lived and leads to the next stage of the reaction.

4. **Transition to Enzyme-Product Complex:**
After the enzyme-substrate complex, a transformation occurs, resulting in the formation of an enzyme-product complex. The enzyme now has converted the substrate into product(s).

5. **Release of Product and Recycling of Enzyme:**
The final step involves the release of the product(s) from the enzyme. Importantly, the enzyme remains unchanged after the reaction and can be reused for subsequent reactions. This characteristic of enzymes allows them to catalyze multiple reactions without being consumed.

6. **Effect on Reaction Rate:**
Enzymes significantly increase the rate of reactions by lowering the activation energy required for the reaction to proceed. This means that reactions can occur more quickly than they would without the enzyme.

7. **Conclusion:**
All the features mentioned in the options (the ability to form enzyme-substrate and enzyme-product complexes, the recycling of enzymes, and the acceleration of reaction rates) are unique characteristics of enzymes. Therefore, the correct answer is that all the options are correct.

**Final Answer:**
All of the above are unique features about enzymes.

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