Which set of factors can move the oxygen dissociation curve towards the right ?

Options

A. High Temperature High PH
B. Low `pO_2` and Low pH
C. High `pO_2` and Low pH
D. Low `pCO_2` and High pH

Answer

To determine which set of factors can move the oxygen dissociation curve towards the right, we need to analyze the effects of various factors on hemoglobin's ability to bind oxygen. The oxygen dissociation curve illustrates the relationship between the partial pressure of oxygen (PO2) and the percentage saturation of hemoglobin with oxygen.

### Step-by-Step Solution:

1. **Understanding the Oxygen Dissociation Curve**:
- The curve is typically sigmoid in shape and represents how readily hemoglobin binds to oxygen at different PO2 levels.
- A rightward shift in the curve indicates a decrease in hemoglobin's affinity for oxygen, meaning it releases oxygen more readily.

2. **Factors Affecting the Curve**:
- **Partial Pressure of Oxygen (PO2)**:
- High PO2 favors the formation of oxyhemoglobin (shifts curve left).
- Low PO2 does not favor binding (shifts curve right).
- **Partial Pressure of Carbon Dioxide (PCO2)**:
- High PCO2 decreases the affinity of hemoglobin for oxygen (shifts curve right).
- Low PCO2 increases affinity (shifts curve left).
- **pH Level**:
- Low pH (high concentration of H+ ions) decreases the affinity of hemoglobin for oxygen (shifts curve right).
- High pH increases affinity (shifts curve left).
- **Temperature**:
- High temperature decreases the affinity of hemoglobin for oxygen (shifts curve right).
- Low temperature increases affinity (shifts curve left).

3. **Analyzing the Options**:
- **Option A: High temperature and high pH**:
- High temperature shifts right (lowers affinity), but high pH shifts left (increases affinity). This option is incorrect.
- **Option B: Low PO2 and low pH**:
- Low PO2 shifts right (lowers affinity), and low pH shifts right (lowers affinity). This option is correct.
- **Option C: High PO2 and low pH**:
- High PO2 shifts left (increases affinity), while low pH shifts right (lowers affinity). This option is incorrect.
- **Option D: Low PCO2 and high pH**:
- Both factors shift left (increase affinity). This option is incorrect.

4. **Conclusion**:
- The correct answer is **B: Low PO2 and low pH**, as both factors contribute to a rightward shift in the oxygen dissociation curve.