1. Objectives 7.3 Cell Transport -Describe passive transport. -Describe active transport.

2. Lesson Overview Lesson Overview Cell Transport Types of Passive Transport 1. Diffusion 2. Facilitated Diffusion 3. Osmosis Passive Transport requires NO ENERGY. Molecules move down their concentration gradient. HIGH to LOW concentration.

3. Lesson Overview Lesson Overview Cell Transport Diffusion The movement of particles from an area of high concentration to an area of low concentration is DIFFUSION.

4. Lesson Overview Lesson Overview Cell Transport Facilitated Diffusion Cell membranes have proteins that act as carriers, or channels, making it easy for certain molecules to cross in a process known as facilitated diffusion.

5. Lesson Overview Lesson Overview Cell Transport Osmosis The movement of WATER MOLECULES from an area of high concentration to an area of low concentration.

6. Lesson Overview Lesson Overview Cell Transport Isotonic Solution Concentration is EQUAL inside and outside of the cell.

7. Lesson Overview Lesson Overview Cell Transport Hypertonic Solutions Concentration is higher OUTSIDE the cell. Water LEAVES the cell. Cell SHRIVELS up from water loss.

8. Lesson Overview Lesson Overview Cell Transport Hypotonic Solution Concentration is higher INSIDE the cell. Water ENTERS the cell. The cell swells and may, ultimately, burst or lyse.

9. Lesson Overview Lesson Overview Cell Transport

10. Lesson Overview Lesson Overview Cell Transport Types of Active Transport 1. Endocytosis 2. Exocytosis 3. Sodium-Potassium Pump Active transport requires ENERGY. Cells sometimes must move materials AGAINST a concentration gradient. LOW to HIGH concentration.

11. Lesson Overview Lesson Overview Cell Transport Endocytosis Endocytosis is the process of taking material into the cell.

12. Lesson Overview Lesson Overview Cell Transport Exocytosis When material is RELEASED from the cell, a process known as exocytosis.

13. Lesson Overview Lesson Overview Cell Transport Sodium Potassium Pump Sometimes pumps are needed to force molecules to move AGAINST their concentration gradient (from an area of LOW to HIGH concentration). The sodium potassium pump is used ESPECIALLY in the nervous and muscular systems.