what is diffusion pressure, osmotic pressure,turgor pressure,diffusion pressure deficit or suction pressure?........how are they related to each other.....i mean which of them are directly proportional or inversely proportional to each other?
The actual pressure exerted by the protoplasm inside the plant cell against the cell wall is termed as Turgor pressure (TP). It is also called turgidity. Plants rely on turgidity to maintain rigidity.
The maximum amount of pressure that can be developed in a solution separated from pure water by a semipermeable membrane is termed Osmotic pressure (OP).
The potential ability of a molecule or ion to diffuse from an area of its greatest concentration to an area of lesser concentration is termed as Diffusion pressure (DP) or suction pressure (SP).
Turgor pressure of a cell is maximum when it is fully turgid and it is reduced as the cell loses water. The actual growth of a cell occurs when TP exceeds wall pressure.
If the two solutions are separated by a semipermeable membrane, the water moves from the solution having less OP to the solution having more OP. The OP is responsible for the movement of water across the semi-permeable membrane.
The diffusion pressure is indirectly proportional to the concentration of diffusing particles. That is greater the concentration of diffusing particles greater the DP and vice versa.