1. Part 3: Homeostasis and Cell Transport (Chapter 5)

2. Passive Transport NO ENERGY REQUIRED to move substances across membrane from a higher concentration to a lower concentration Types: 1.Diffusion 2.Osmosis 3.Facilitated Diffusion 4.Diffusion through Ion Channels Involves the movement of molecules across the cell membrane without an input of energy by the cell.

3. Which types of molecules can move through the membrane without energy? Small, nonpolar (hydrophobic) molecules Examples: O 2, CO 2, H 2 O, lipids

4. Diffusion

5. Osmosis Hypotonic IsotonicHypertonic

6. Facilitated Diffusion

7. Ion Channels

8. Active transport moves molecules across the cell membrane from an area of lower concentration to an area of higher concentration (against concentration gradient) requires cells to use ENERGY (ATP) Some types of active transport are performed by carrier proteins called cell membrane pumps. Active Transport Cell Membrane Pumps and Vesicles

9. Example: Sodium-Potassium Pump

10. Sodium-Potassium Pump

11. Endocytosis and Exocytosis