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Turgor is maintained by the water inside the cell.

Water moves into or out of the cell by osmosis and is based on the water potential of the cell.

Illustration showing a cell with inner turgor pressure pushing outward, while water molocules outside the cell push intward.

The cell's water potential is equal to the sum of the : Ψ = Ψm + Ψπ + Ψp

Matric potential Ψm

Osmotic potential Ψπ

Pressure or turgor potential Ψp

Illustration of water potential formula with turgor pressure spreading in all directions in the cell.

A major way that the cell remains turgid is by keeping a negative osmotic potential in the vacuole where the cell stores sugars, amino acids and organic acids.

Illustration of water potential formula with turgor pressure spreading in all directions in the cell.

Water moves into or out of the cell due to osmosis.

Osmosis is the movement of water across a membrane in response to the osmotic potential on either side of the membrane.

Illustration showing a plant cell with water molecules outside moving into it.

Water moves to areas with more negative osmotic potential. Osmotic potential is measured in bars or megaPascals.

In this example, water will move into the cell because it has the more negative osmotic potential.

Illustration of plant cell with water about to move into it. Outside the plant has -5 bars osmotic potential, while inside the cell has -10 bars.

Water no longer moves into the cell when the water potential inside and outside are at equilibrium (-5 bars).

Illustration of plant cell with water molecules both inside and outside of it. Osmotic potential is -5 bars both inside and out.