Movement of ions in and out of cells is crucial to maintaining homeostasis within the body and ensuring that biological functions run properly. The natural movement of molecules due to collisions is called diffusion. Several factors affect diffusion rate: concentration, surface area, and molecular pumps. This activity demonstrates diffusion, osmosis, and active transport through 12 interactive models. Start by following the path of a molecule of dye in water, create concentration gradients on either side of a cell membrane and watch the movement of substances in and out of a cell, and monitor the movement of oxygen into red blood cells with and without hemoglobin.
The download for this activity will require 70 KB of disk space.