The diffusion pressure deficit of a cell protoplasm is equal to

Options

A. wall pressure
B. turgor pressure
C. osmotic pressure
D. suction pressure

Answer

**Step-by-Step Solution:**

1. **Understand the Concept of Diffusion Pressure Deficit (DPD):**
- DPD refers to the difference in diffusion pressure between pure water and a solution. It indicates the 'thirst' of a cell for water.

2. **Define Key Terms:**
- **Diffusion Pressure:** The pressure exerted by the movement of water molecules from an area of higher concentration (pure water) to an area of lower concentration (solution).
- **Osmotic Pressure:** The pressure required to stop the flow of water into a solution through a semipermeable membrane.
- **Turgor Pressure:** The pressure exerted by the fluid (water) inside the cell against the cell wall.

3. **Formula for DPD:**
- The formula to calculate DPD is:
\[ \text{DPD} = \text{Osmotic Pressure} - \text{Turgor Pressure} \]
- This formula helps in quantifying the actual 'thirst' of the cell for water.

4. **Interpretation of DPD:**
- A DPD of zero indicates that there is no net movement of water into the cell, meaning the cell is in equilibrium with its environment.
- DPD is also referred to as the 'suction pressure' of the cell, which is crucial for maintaining cell turgidity and overall plant health.

5. **Conclusion:**
- The diffusion pressure deficit of a cell protoplasm is equal to the osmotic pressure minus the turgor pressure.

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