The fastest enzyme is

Options

A. Zymase
B. Carbonic anhydrase
C. Amylase
D. Hexokinase

Answer

To determine which enzyme is the fastest among the given options, we need to understand the concept of turnover number. The turnover number is a measure of the efficiency of an enzyme, defined as the number of substrate molecules converted into product by an enzyme molecule in a unit of time, typically expressed in seconds.

### Step-by-Step Solution:

1. **Understand the Concept of Turnover Number**:
- The turnover number (k_cat) indicates how many substrate molecules an enzyme can convert to product per second. A higher turnover number means a more efficient enzyme.

2. **Review the Options**:
- The options provided are:
- Zymase
- Carbonic anhydrase
- Amylase
- Hexokinase

3. **Research the Turnover Numbers of Each Enzyme**:
- **Zymase**: This is a complex of enzymes involved in fermentation, but its specific turnover number is not as high as some others.
- **Carbonic Anhydrase**: Known for its exceptionally high turnover number, it catalyzes the conversion of carbon dioxide and water to bicarbonate and protons.
- **Amylase**: This enzyme breaks down starch into sugars, but its turnover number is lower compared to carbonic anhydrase.
- **Hexokinase**: This enzyme phosphorylates glucose to glucose-6-phosphate, but again, its turnover number is not as high as carbonic anhydrase.

4. **Identify the Fastest Enzyme**:
- Among the options, carbonic anhydrase has a turnover number of approximately 36 million reactions per second, making it the fastest enzyme known.

5. **Conclusion**:
- Therefore, the fastest enzyme from the given options is **Carbonic Anhydrase**.

### Final Answer:
The fastest enzyme is **Carbonic Anhydrase**.