Right-shift of oxygen-haemoglobin dissociation curve can occur due to

Options

A. High pH
B. Low temperature
C. High `H^+` concentration
D. Low `pCO_2`

Answer

To answer the question regarding the right-shift of the oxygen-hemoglobin dissociation curve, we will analyze the factors that can cause this shift.

### Step-by-Step Solution:

1. **Understanding the Oxygen-Hemoglobin Dissociation Curve**:
- The oxygen-hemoglobin dissociation curve illustrates the relationship between the partial pressure of oxygen (pO2) and the saturation of hemoglobin with oxygen.
- A right shift in this curve indicates a decrease in hemoglobin's affinity for oxygen, meaning hemoglobin releases oxygen more readily to the tissues.

2. **Factors Leading to Right Shift**:
- Several physiological factors can cause a right shift in the curve:
- **Increased Partial Pressure of Carbon Dioxide (pCO2)**: Higher levels of carbon dioxide in the blood lead to a decrease in pH (more acidic conditions), promoting oxygen release.
- **Decreased pH (Increased H+ Ion Concentration)**: A lower pH (more acidic) increases the concentration of hydrogen ions (H+), which also promotes a right shift.
- **Increased Temperature**: Higher temperatures reduce hemoglobin's affinity for oxygen, facilitating oxygen release.
- **Increased 2,3-Bisphosphoglycerate (2,3-BPG)**: This metabolite increases in red blood cells during conditions of low oxygen, promoting oxygen release.

3. **Evaluating the Given Options**:
- **High pH Value**: This would not cause a right shift; it would actually favor a left shift (higher affinity for oxygen).
- **Low Temperature**: This would not cause a right shift; higher temperatures are needed for a right shift.
- **High H+ Ion Concentration**: This is correct as it indicates lower pH, which promotes a right shift.
- **Low pCO2**: This would not cause a right shift; higher pCO2 is needed for a right shift.

4. **Conclusion**:
- The correct answer is that a right shift of the oxygen-hemoglobin dissociation curve can occur due to **high H+ ion concentration** (which corresponds to lower pH).

### Final Answer:
The right-shift of the oxygen-hemoglobin dissociation curve can occur due to **high H+ ion concentration**.