Blood hemoglobin has high affinity for

Options

A. `CO_(2)`
B. CO
C. `O_(2)`
D. `H_(2)`

Answer

To solve the question "Blood hemoglobin has high affinity for", we need to analyze the options given and understand the properties of hemoglobin.

### Step-by-Step Solution:

1. **Understanding Hemoglobin**:
- Hemoglobin is a protein found in red blood cells (RBCs) that is primarily responsible for transporting oxygen from the lungs to the rest of the body.
- It consists of a heme group that contains an iron atom at its center, which is crucial for its function.

2. **Analyzing the Options**:
- The options provided are:
- A) CO2 (Carbon Dioxide)
- B) CO (Carbon Monoxide)
- C) O2 (Oxygen)
- D) H2 (Hydrogen)
- We need to determine which of these gases hemoglobin has the highest affinity for.

3. **Affinity of Hemoglobin**:
- Hemoglobin has a higher affinity for smaller molecules.
- Among the options, carbon monoxide (CO) is a smaller molecule compared to carbon dioxide (CO2), oxygen (O2), and hydrogen (H2).

4. **Comparing Affinities**:
- Research shows that carbon monoxide binds to hemoglobin with a much higher affinity than oxygen. In fact, carbon monoxide has about 210 times greater affinity for hemoglobin than oxygen.
- This strong binding occurs because the electron coordination between the heme iron and carbon monoxide is perpendicular to the heme plane, which facilitates a stronger bond.

5. **Conclusion**:
- Based on the analysis, the correct answer to the question "Blood hemoglobin has high affinity for" is **B) CO (Carbon Monoxide)**.