A solution will be hypertonic to a cell if its solute concentration is higher than inside the cell, and the solutes cannot cross the membrane.
- If a cell is placed in a hypertonic solution, there will be a net flow of water out of the cell, and the cell will lose volume.
- If a cell is placed in a hypotonic solution, there will be a net flow of water into the cell, and the cell will gain volume.
- Isotonic solutions have equal (iso-) concentrations of substances.
- Water potentials are thus equal; although there will still be equal amounts of water movement in and out of the cell, the net flow is zero.