Question

Write a note on Diffusion pressure deficit (DPD).​

Answer 1

Answer:

Diffusion Pressure Deficit (DPD):

• Diffusion pressure deficit (DPD) is the difference between diffusion pressure of pure water and solution.

• DPD is also called suction force (SF) or suction pressure (SP).

• DPD, i.e. diffusion pressure deficit of a solution is initially equal to its osmotic pressure (OP).

• When water enters into a cell, the increasing turgor pressure (TP), forces the cytoplasm against cell wall.

• The cell wall exerts an equal and opposite pressure (WP) on the cell sap. This can be represented as:

DPD = OP-TP (WP)

In this, DPD is diffusion pressure deficit, OP is osmotic pressure, TP is turgor pressure and WP is wall pressure.

Answer 2

Answer:

The term diffusion pressure deficit (DPD) was coined by B.S Meyer in 1938. Originally DPD was described as suction pressure by Renner (1915). It is a reduction in the diffusion pressure of water in solution or cell over its pure state due to the presence of solutes in it and forces opposing diffusion.