Diffusion & Membranes: free biology simulation
Remove the divider or open membrane channels and watch particles spread down their concentration gradient.
▶ Open the simulationFree, no sign-up. Works on phones, tablets and laptops.
The science
Particles move randomly, and that random motion spreads them out from where they are concentrated to where they are not. This net movement down a concentration gradient is diffusion. Membranes with channels only let some particles through.
Things to try
- Remove the divider and time how long mixing takes.
- Watch the concentrations on both sides even out over time.
- Open only a few membrane channels.
Topics covered
concentration gradient osmosis membrane channels random walk
How to use it
Open the simulation, then change the experiment live with the sliders, checkboxes and buttons in the side panel. Drag objects on screen where it makes sense, and use Pause, Step, Speed and Reset in the bottom bar to study every moment.
Frequently asked questions
What does the Diffusion & Membranes simulation show?
Particles move randomly, and that random motion spreads them out from where they are concentrated to where they are not. This net movement down a concentration gradient is diffusion. Membranes with channels only let some particles through.
Is the Diffusion & Membranes simulation free?
Yes. It runs free in any web browser on phones, tablets and laptops, with no sign-up or download.