Hank explains diffusion and demonstrates the diffusion process by placing dyed salt water (in a sausage casing) in a glass of water. The casing represents the membrane, and over several hours, the salt water diffuses into the pure water. Diffusion ends when the salt content is the same inside and outside of the casing.

Key Words: Active Transport, Passive Transport, Diffusion, Osmosis, Solutions, Hypertonic, Hypotonic, Isotonic, Aquaporins