Osmosis

Definition

The process by which a solvent (usually water) moves across a semi-permeable membrane from a region of high water concentration to a region of low water concentration, driven by the difference in solute concentrations.

Etymology

From Greek 'osmos', meaning 'impulse' or 'thrust'.

Example

Osmosis plays a vital role in maintaining cell turgor pressure in plants.

Related Terms

• Diffusion
• Membrane permeability

Usage Notes

Osmosis is a passive process that does not require energy input from the cell.