In: Biology
4) Write the mathematical expression for water potential (includes solute and pressure potential) and give a brief definition for each variable.
Ans. The free energy associated with water is known as water potential. It is calculated in Bar/Megapascal/Atmosphere.
Components of water potential-
1. Matrix potential- When an imbibant adsorsb any imbibe at its surface, it exerts a pressure on its surrounding. This pressure is known as matrix potential or imbition pressure.
2.Pressure potential- when water continues to enter the cell, expanding plasma membrane exerts a pressure on cell wall.This hydrostatic pressure is known as pressure potential.
3. Gravity potential- Gravity causes water to move downward unless force of gravity is opposed by an equal and opposite force. Gravity potential depends on height of water, density of water and gravity.
4.Solute potential- it is also known as osmotic potential which represents the effect of dissolved solute on water potential.