Water potential

Definition

Water potential is a measure of the potential energy in water and drives the movement of water through plants. It is influenced by factors like solute concentration and pressure.

5 Must Know Facts For Your Next Test

1. Water potential is measured in units of pressure called megapascals (MPa).
2. Water moves from areas of higher water potential to areas of lower water potential.
3. Components that affect water potential include solute potential (osmotic potential) and pressure potential.
4. Pure water at atmospheric pressure has a water potential of zero.
5. In plant cells, turgor pressure contributes positively to water potential, while solutes contribute negatively.

Review Questions

• What are the main components that influence water potential?
• How does the presence of solutes affect the water potential of a solution?
• Why does pure water have a water potential of zero?

Related terms

Solute Potential: A component of water potential that accounts for the effect of solute concentration; also known as osmotic potential.

Pressure Potential: The physical pressure exerted on or by a solution, which can affect its overall water potential.

Turgor Pressure: The internal pressure within plant cells exerted by the cell membrane against the cell wall, contributing to structural rigidity and overall cell function.