The enzyme that increases the reaction rate between `CO_(2)` and `H_(2)O` in red blood cell is

Options

A. carbonic anhydrase
B. adenylate cyclase
C. carbonic synthetase
D. alkaline phosphatase.

Explanation

To answer the question regarding the enzyme that increases the reaction rate between carbon dioxide (CO₂) and water (H₂O) in red blood cells (RBC), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reaction**: The reaction in question involves carbon dioxide (CO₂) and water (H₂O) combining to form carbonic acid (H₂CO₃). This reaction is crucial for the transport of CO₂ in the blood.

2. **Understand the Role of Enzymes**: Enzymes are biological catalysts that speed up chemical reactions. In the context of the reaction between CO₂ and H₂O, we need to identify which enzyme facilitates this process in red blood cells.

3. **List the Options**: The options provided are:
- A) Carbonic anhydrase
- B) Adenylate cyclase
- C) Carbonic synthetase
- D) Alkaline phosphatase

4. **Recall the Function of Carbonic Anhydrase**: Carbonic anhydrase is an enzyme that catalyzes the conversion of CO₂ and H₂O into carbonic acid (H₂CO₃). It also facilitates the dissociation of carbonic acid into bicarbonate ions (HCO₃⁻) and protons (H⁺).

5. **Determine the Correct Answer**: Among the options, carbonic anhydrase is specifically known for its role in speeding up the reaction between CO₂ and H₂O in red blood cells. This enzyme significantly increases the reaction rate, making it thousands of times faster than it would be without the enzyme.

6. **Conclusion**: Therefore, the correct answer to the question is **A) Carbonic anhydrase**.