Water potential

Front

What is water potential?

Back

Water potential ( Ψ ) is the potential energy of water in a system compared to pure water, measured in megapascals (MPa). 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, and it decreases as solute concentration increases.

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 negative (tension in xylem).

Front

How does water move in relation to water potential?

Back

Water moves from areas of higher water potential (less negative) to areas of lower water potential (more negative).

Front

What happens to a cell in a hypertonic solution?

Back

A cell in a hypertonic solution will lose water and shrink because the solute concentration outside the cell is higher than inside.

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What happens to a cell in a hypotonic solution?

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A cell in a hypotonic solution will gain water and swell because the solute concentration outside the cell is lower than inside.

Front

What is isotonic solution?

Back

An isotonic solution has the same solute concentration as the cell, resulting in no net movement of water into or out of the cell.

Front

What is the effect of adding solutes to a solution on solute potential?

Back

Adding solutes to a solution decreases the solute potential ( Ψs ) because it becomes more negative.

Front

What is the relationship between water potential and cell turgor?

Back

Cell turgor is maintained when the pressure potential ( Ψp ) is positive, which occurs when water enters the cell and pushes against the cell wall.

Front

What is the formula for calculating water potential?

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The formula for water potential is: @@ Ψ = Ψs + Ψp@@.