Osmosis is the diffusion of water across a membrane from an area of higher water concentration (lower solute concentration) to lower water concentration (higher solute concentration).
In an isotonic environment, both the water and solute concentration are the same inside and outside the cell and water flows into and out of the cell at an equivalent rate.

Flash Animation Illustrating Osmosis in an Isotonic Environment.swf by Gary E. Kaiser, Ph.D.
Professor of Microbiology, The Community College of Baltimore County, Catonsville Campus
This work is licensed under a Creative Commons Attribution 4.0 International License.
Based on a work at http://faculty.ccbcmd.edu/~gkaiser/index.html.

Last updated: Feb., 2018
Please send comments and inquiries to Dr. Gary Kaiser