Water Potential

Flashcards covering the key concepts of water potential, its components, and its effects on plant cells.

Water Potential (ψw)

The potential energy of water per unit volume, relative to pure water, used to quantify the tendency of water to move from dilute to concentrated solutions due to osmosis. Measured in kilopascals (kPa).

Movement of Water

Water moves from areas of higher water potential to areas of lower water potential to minimize differences in potential energy.

Solute Potential (Ψs)

The component of water potential that is established when a solute dissolves in water; dissolving a solute lowers the water potential, making it negative.

Pressure Potential (Ψp)

The component of water potential influenced by hydrostatic pressure, which can be affected if pressure rises or sinks above or below atmospheric pressure.

Water Potential Equation

ψw = ψs + ψp (Water potential is the sum of solute potential and pressure potential)

Hypotonic Solution (Plant Tissue)

When plant tissue is immersed in a hypotonic solution, water moves into the cell, increasing pressure (Ψp), decreasing Ψs, and overall increasing Ψw.

Hypertonic Solution (Plant Tissue)

When plant tissue is immersed in a hypertonic solution, water moves out of the cell, decreasing pressure (Ψp), increasing Ψs, and overall decreasing Ψw.