The affinity of CO with Hb is more than oxygen by

Options

A. 2 times
B. 20 times
C. 200 times
D. 2000 times

Answer

### Step-by-Step Solution:

1. **Understanding Hemoglobin**: Hemoglobin is a red-colored protein found in red blood cells (RBCs) that is responsible for transporting gases, primarily oxygen (O2) and carbon dioxide (CO2), in the blood.

2. **Gas Binding**: Hemoglobin can bind to both oxygen and carbon monoxide. The binding of these gases to hemoglobin is crucial for their transport throughout the body.

3. **Comparative Affinity**: The question asks about the relative affinity of carbon monoxide (CO) compared to oxygen (O2). Affinity refers to how readily a gas binds to hemoglobin.

4. **Research Findings**: Studies show that carbon monoxide has a significantly higher affinity for hemoglobin than oxygen. Specifically, carbon monoxide binds to hemoglobin approximately 200 times more readily than oxygen.

5. **Stable Compound Formation**: When carbon monoxide binds to hemoglobin, it forms a stable compound (carboxyhemoglobin) that is difficult to dissociate. This means that even in the presence of oxygen, carbon monoxide can effectively "block" the binding sites on hemoglobin, reducing the amount of oxygen that can be transported.

6. **Conclusion**: Therefore, the correct answer to the question is that the affinity of carbon monoxide with hemoglobin is more than that of oxygen by **200 times**.