Which of he following increases the oxygen affinity of Hb?

Options

A. decrease in pH
B. decrease in acidity
C. decrease in temperatuere
D. decrease in `co_(2)` concentration

Answer

To determine which factors increase the oxygen affinity of hemoglobin (Hb), we can analyze each option provided in the question. Here’s a step-by-step solution:

### Step 1: Understand Hemoglobin's Oxygen Affinity
Hemoglobin's affinity for oxygen is influenced by various physiological factors, including pH, temperature, and carbon dioxide concentration.

### Step 2: Analyze Each Option
1. **Decrease in pH**: A decrease in pH (increased acidity) leads to a lower affinity of hemoglobin for oxygen. This is known as the Bohr effect.
- **Conclusion**: This option does not increase oxygen affinity.

2. **Decrease in Acidity**: A decrease in acidity means an increase in pH. Higher pH (less acidic conditions) increases the affinity of hemoglobin for oxygen.
- **Conclusion**: This option increases oxygen affinity.

3. **Decrease in Temperature**: Lower temperatures enhance the binding of oxygen to hemoglobin, thus increasing its affinity for oxygen.
- **Conclusion**: This option increases oxygen affinity.

4. **Decrease in Carbon Dioxide Concentration**: A lower concentration of carbon dioxide in the blood also increases the affinity of hemoglobin for oxygen, as it reduces the acidity (increased pH) and shifts the oxygen dissociation curve to the left.
- **Conclusion**: This option increases oxygen affinity.

### Step 3: Final Answer
The factors that increase the oxygen affinity of hemoglobin are:
- Decrease in acidity (which increases pH)
- Decrease in temperature
- Decrease in carbon dioxide concentration