AP Biology Water Potential Problems

Front

What is water potential?

Back

Water potential (ψ) is the potential energy of water in a system compared to pure water, measured in bars. It determines the direction of water movement.

Front

What is solute potential?

Back

Solute potential (ψs) is the component of water potential that is due to the presence of solute molecules. It is always negative or zero.

Front

What is pressure potential?

Back

Pressure potential (ψp) is the physical pressure on a solution, which can be positive (turgor pressure in plant cells) or zero.

Front

How do you calculate water potential?

Back

Water potential (ψ) is calculated using the formula: ψ = ψs + ψp.

Front

What happens to water movement when a cell is placed in a hypertonic solution?

Back

Water will move out of the cell, causing it to shrink.

Front

What happens to water movement when a cell is placed in a hypotonic solution?

Back

Water will move into the cell, causing it to swell.

Front

What is the water potential of a cell with a solute potential of -4 bars and a pressure potential of 2 bars?

Back

The water potential is -2 bars (ψ = ψs + ψp = -4 + 2).

Front

If a plant cell has a water potential of -3 bars and is placed in a solution with a water potential of -5 bars, which way will water move?

Back

Water will move into the cell, as the cell has a higher water potential.

Front

What is the solute potential of a 0.50M sucrose solution at 25 degrees Celsius?

Back

The solute potential is -12 bars.

Front

What is the significance of turgor pressure in plant cells?

Back

Turgor pressure helps maintain cell structure and rigidity, allowing plants to stand upright.