Describe the concept of water potential w and understand th

Describe the concept of water potential ( w) and understand the relationship of its components (S, p and G). How does water potential explain the movement of water within a plant?

Solution

Water potential is fundamental concept to understand water movement. Solute potential and pressure potential arr two main components that determine water potential.

Water molecules possess the kinetic energy , the greater the concentration of water in a system the greater is its kinetic energy or water potential. If two systems containing water are in contact , the random movement of water molecule takes place, which is net movement of water molecules with the system of higher energy to one with the lower energy .

water potential of pure water is taken to be 0. If solute is added into pure water, the solution has fewer water, the water potential of solution decreases. This magnitude of lowering due to dissolution of solute is called as solute potential. It is always negative.

If pressure more than atmospheric pressure is applied to a system, its water potential increases. Pressure that builds up in the plant making the cells turgid is called as pressure potential. It is usually positive. Negative pressure potential causes the water movement up in the stem of plant through xylem

Water potential= solute potential+ pressure potential