Hb most strongly combines with

Options

A. CO
B. `O_(2)`
C. `CO_(2)`
D. `O_(3)`

Answer

**Step-by-Step Solution:**

1. **Understanding Hemoglobin (Hb):** Hemoglobin is a protein found in red blood cells that is responsible for transporting oxygen from the lungs to the rest of the body and returning carbon dioxide from the body back to the lungs.

2. **Identifying the Options:** The question provides four options for what hemoglobin most strongly combines with:
- CO (Carbon Monoxide)
- O2 (Oxygen)
- CO2 (Carbon Dioxide)
- O3 (Ozone)

3. **Analyzing Affinity:** Hemoglobin has different affinities for these gases:
- It has the highest affinity for carbon monoxide (CO). This means that hemoglobin binds more strongly to carbon monoxide than to any other gas.
- The next highest affinity is for oxygen (O2). Hemoglobin binds to oxygen to transport it throughout the body.
- Carbon dioxide (CO2) has a lower affinity compared to oxygen.
- Ozone (O3) is not typically relevant in the context of hemoglobin binding.

4. **Conclusion:** Given that hemoglobin has the strongest binding affinity for carbon monoxide, the correct answer to the question is CO (Carbon Monoxide).

**Final Answer:** Hemoglobin most strongly combines with CO (Carbon Monoxide).

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