Biology

Confusing Diffusion and Osmosis

Students call any movement across a membrane osmosis, even when the moving particles are not water.

Quick check

Why students make it

A membrane makes students think the process must be osmosis. They remember that osmosis involves a membrane, but they forget that osmosis specifically means water movement.

The rule done right

Diffusion is the movement of particles from higher concentration to lower concentration. Osmosis is the diffusion of water, H2O\mathrm{H_2O}, across a selectively permeable membrane from lower solute concentration toward higher solute concentration.

Related resources

cell-transportdiffusionosmosis