Concept 2 Review: Isotonic, Hypotonic, and Hypertonic Solutions
Water moves readily across cell membranes through special protein-lined channels, and if the total concentration of all dissolved solutes is not equal on both sides, there will be net movement of water molecules into or out of the cell. Whether there is net movement of water into or out of the cell and which direction it moves depends on whether the cellís environment is isotonic, hypotonic, or hypertonic.

Cells in Isotonic Solutions