Tonicity and Osmoregulation

Tonicity

The ability of an extracellular solution to cause a cell to gain or lose water

Depends on concentration of solutes that CANNOT pass through membrane

Osmoregulation

Cells must be able to regulate their solute concentrations and maintain water balance

Isotonic solution

Cells emerged will have no net movement - water diffuses into cell at the same rate

Hypertonic solution

Cells lose water to their extracellular surroundings b/c concentration of solutes is higher outside of the cell

Hypotonic solution

Cells gain water b/c concentration of water is lower than outside of cell

Plasmolysis

Vacuole shrinks and the plasma membrane pulls away from the cell wall

Lyse

Disintegration due to rupture of the cell membrane

Plant cells in hypotonic solution

Plant cells work optimally b/c of cell wall

Water potential

A physical property that predicts the direction water will flow