Concentration Gradient When molecules move “with the concentration gradient” they move from area of high concentration to low concentration. When molecules move “against the concentration gradient” they move from area of low concentration to high concentration.
Diffusion The movement of molecules from high concentration to lower concentration. Spreading out. http://www.wisc- online.com/Objects/ViewObject.aspx?ID=AP19 03 http://www.stolaf.edu/people/giannini/flashan imat/transport/diffusion.swf