The Selectively permeable Cell Membrane

Diffusion, osmosis, and active transport

• Diffusion is the movement of particles from an area of higher concentration to an area of lower concentration.

• Osmosis occurs when water particles move from a higher concentration to a lower concentration

• Explain how placing this wilted flower in water will cause the flower to “straighten up”.

Example 1: Equal movement of water in and out of cells

Example 2: More water moving into cells than is moving out

Example 3: More water moving out of cells than is moving in

Active Transport (sugar)