Diffusion

These two animations show the basic process of diffusion across a plasma membrane (the vertical blue and orange structure). Both versions start with a concentration difference across the plasma membrane and proceeds to equilibrium. Note that diffusion "goes from the higher concentration side to the lower concentration side". Also, there is no energy input into the system to cause diffusion; it simply occurs due to the random motion of the substance moving across the plasma membrane.


Click to See Diffusion.


Click to See Diffusion with Flow Arrows.