1. Cell Transport Overview
Passive
Diffusion
Osmosis Facilitated
Active
Pumps Vesicles

2. 2.12 Osmosis Diffuse water across membrane
High water conc.  low water conc.
No ATP
Water movement is important when the other particles can’t diffuse.

3. Osmosis Direction
More solute = less water Water moves from low solute  high solute Solutes suck
Water movement is important when the other particles can’t diffuse.

4. Equilibrium
Isotonic: equal solute Hypertonic: more solute Hypotonic: less solute

5. Osmosis Problems
So if you are stranded in the ocean and drink saltwater, what will happen? If I take nemo, an ocean fish, and put him in my freshwater fish tank, what will happen?

6. Frame of Reference
Fish cells vs. Aquarium water

8. Plants vs. Animals

12. 2.13 Facilitated Diffusion
Diffusion via protein
Larger & polar
Charged (ions)
Direction?
Energy?

13. Proteins
Ion channels Carriers (Change shape)

14. 2.14 Active Transport Low to high conc. Use Energy (ATP) 3 types:
Protein pumps
Vesicles (Endo and Exo)

15. Protein Pumps Integral proteins Change shape with ATP Calcium pump
Proton (H+) pump

16. Gradients
Many cells use gradients (energy/signals)
Muscles/Nerves

17. 2.15 Sodium Potassium Pump
3 Na+ out : 2 K+ in
ATP = shape change

18. Na/K Pump Gradients
More Na+ outside More K+ inside More Positive outside

19. 2.16 Vesicle Transport Exocytosis Release big/bulk objects
Merge Vesicle
Insides  outside

20. 2.16 Vesicle Transport Endocytosis Ingest large objects
Phagocytosis – eat
Pinocytosis – drink
Receptor-mediated – specific