Water Potential and Osmosis Concepts

Front

What is water potential?

Back

Water potential ( Ψ ) is the measure of the potential energy in water, influencing the direction of water movement. It is affected by solute concentration and pressure.

Front

How does solute concentration affect water potential?

Back

Increasing solute concentration decreases water potential.

Front

What is the formula for calculating water potential?

Back

The formula is: @@ Ψ = Ψ_s + Ψ_p@@, where Ψ_s is solute potential and Ψ_p is pressure potential.

Front

What is solute potential?

Back

Solute potential ( Ψ_s) is the component of water potential that is due to the presence of solutes. It is always negative or zero.

Front

What is pressure potential?

Back

Pressure potential ( Ψ_p) is the physical pressure on a solution, which can be positive (in a plant cell) or zero (in an open container).

Front

What is the pressure potential of a solution in an open container at sea level?

Back

The pressure potential is 0.

Front

What is the equation used to calculate solute potential?

Back

The equation is: @@ Ψ_s = -iCRT@@, where i is the ionization constant, C is the molar concentration, R is the pressure constant, and T is the temperature in Kelvin.

Front

If a cell's Ψ_p = 3 bars and Ψ_s = -4.5 bars, what is the resulting Ψ?

Back

The resulting water potential is -1.5 bars.

Front

Calculate the water potential of a solution with a solute potential of -2.5 bars and a pressure potential of 0.9 bars.

Back

The water potential is -1.6 bars.

Front

What happens to water potential when solute is added to a solution?

Back

Adding solute decreases the water potential.