Turgor pressure

Look up turgid in Wiktionary, the free dictionary.

Turgor pressure is the force within the cell that pushes the plasma membrane against the cell wall.^[1]

It is also called hydrostatic pressure, and is defined as the pressure in a fluid measured at a certain point within itself when at equilibrium.^[2] Generally, turgor pressure is caused by the osmotic flow of water and occurs in plants, fungi, and bacteria. The phenomenon is also observed in protists that have cell walls.^[3] This system is not seen in animal cells, as the absence of a cell wall would cause the cell to lyse when under too much pressure.^[4] The pressure exerted by the osmotic flow of water is called turgidity. It is caused by the osmotic flow of water through a selectively permeable membrane. Movement of water through a semipermeable membrane from a volume with a low solute concentration to one with a higher solute concentration is called osmotic flow. In plants, this entails the water moving from the low concentration solute outside the cell into the cell's vacuole.^{[citation needed]}