1. Osmosis & Diffusion

2. Diffusion *The movement of molecules from an area of HIGH concentration to an area of LOW concentration.

3. Examples of Diffusion Tea Perfume Flatulence

4. Diffusion Diffusion does NOT use energy. When the particles are balanced on both sides of a membrane, EQUILIBRIUM has been reached.

5. Osmosis The diffusion of water across a selectively permeable membrane.

6. Osmosis Osmosis does NOT use energy. Ex. Top of page 101 “Why does the side with more sugar molecules rise?” Osmotic pressure will force the water to move from an area of low water concentration to an area of high water concentration.

7. Blood example: Bottom of p. 101 Hypotonic (LOW)-Refers to the solution outside the cell. Hypertonic (HIGH)-Refers to the solution outside the cell. Isotonic (EQUAL)-Refers to the solution outside the cell.

8. Facilitated Diffusion A carrier protein helps to move another particle across the cell membrane. Energy is NOT used. But can only work if there is a concentration gradient.

9. Active Transport DOES require energy. A protein channel, pushes certain molecules across the cell membrane. Examples: Calcium, potassium and sodium ions are pushed across. They usually cannot diffuse across by themselves.

10. Endocytosis “endo= in & cytosis =cell” So, this word means “into the cell”. A form of active transport, so does use energy Phagocytosis = “Cell Eating” Pinocytosis = “Cell Drinking”

11. Exocytosis “exo=OUT cytosis=CELL Getting rid of excess water or waste.