Cell Transport

1. Cell Transport

2. Diffusion • Random movement of liquid/gas particles from an area with ________________ to an area of ____________________.

3. Concentration Gradient • High to low.

4. Concentration Gradient • High to low. • The greater the difference in concentration – the faster the rate of diffusion.

5. Concentration Gradient • High to low. • The greater the difference in concentration – the faster the rate of diffusion. • Diffusion DOES NOT REQUIRE ENERGY.

6. Concentration Gradient • High to low. • The greater the difference in concentration – the faster the rate of diffusion. • Diffusion DOES NOT REQUIRE ENERGY. • Small particles diffuse faster than large – EG. The smell of ammonia diffuses more rapidly than onion smell.

7. Diffusion • Concentration Gradient = High to low. • The greater the difference in concentration – the faster the rate of diffusion. • Diffusion DOES NOT REQUIRE ENERGY. • Small particles diffuse faster than large – EG. The smell of ammonia diffuses more rapidly than onion smell. • Food & O2 diffuse into cells, and waste diffuses out. (EG. CO2)

8. Rate of Diffusion • Depends on temperature of liquid or gas.

9. Rate of Diffusion • Depends on temperature of liquid or gas. • The state of the matter being diffused (either liquid or gas).

10. Rate of Diffusion • Depends on temperature of liquid or gas. • The state of the matter being diffused (either liquid or gas). • The concentration on chemicals. YOU ALREADY KNOW THIS THOUGH RIGHT!

11. Facilitated diffusion • Cell membrane can contain transport proteins (elevators!). • This allows certain chemicals across a membrane faster than others.

12. Facilitated diffusion • Cell membrane can contain transport proteins (elevators!). • This allows certain chemicals across a membrane faster than others. • Water can diffuse easily, but glucose needs help – proteins are there to move it across the membrane.

13. Facilitated Diffusion • http://www.youtube.com/watch?v=JShwXBWGMyY&feature=fvsr

14. Osmosis – diffusion of water molecules across a partially permeable membrane from higher to lower concentration of water molecules.

15. Osmosis – diffusion of water molecules across a partially permeable membrane from higher to lower concentration of water molecules. • Direction of net movement can be predicted on the basis of relative concentrations of water and solute molecules in the solutions involved.

16. Osmosis – diffusion of water molecules across a partially permeable membrane from higher to lower concentration of water molecules. • Direction of net movement can be predicted on the basis of relative concentrations of water and solute molecules in the solutions involved. • When cells are placed in an environment of different concentration, there is an osmotic gradient between the external/internal environments. Cytoplasm is a solute.

17. Osmosis – diffusion of water molecules across a partially permeable membrane from higher to lower concentration of water molecules. • Direction of net movement can be predicted on the basis of relative concentrations of water and solute molecules in the solutions involved. • When cells are placed in an environment of different concentration, there is an osmotic gradient between the external/internal environments. Cytoplasm is a solute. • Hypotonic – High concentration of water, low concentration of solute.

18. Osmosis – diffusion of water molecules across a partially permeable membrane from higher to lower concentration of water molecules. • Direction of net movement can be predicted on the basis of relative concentrations of water and solute molecules in the solutions involved. • When cells are placed in an environment of different concentration, there is an osmotic gradient between the external/internal environments. Cytoplasm is a solute. • Hypotonic – High concentration of water, low concentration of solute. • Hypertonic – Low concentration of water, high concentration of solute.

19. Osmosis • http://www.youtube.com/watch?v=sdiJtDRJQEc

20. Osmoregulation – in plants • Remember there is a large vacuole in plants.

21. Osmoregulation – in plants • Remember there is a large vacuole in plants. • If this loses water, the cells become floppy and the cytoplasm pulls away from the cell wall.

22. Osmoregulation – in plants • Remember there is a large vacuole in plants. • If this loses water, the cells become floppy and the cytoplasm pulls away from the cell wall =

23. Osmoregulation – in plants • Remember there is a large vacuole in plants. • If this loses water, the cells become floppy and the cytoplasm pulls away from the cell wall = the plant will wilt.

24. Osmoregulation – in plants • Remember there is a large vacuole in plants. • If this loses water, the cells become floppy and the cytoplasm pulls away from the cell wall = the plant will wilt. • Vacuoles can become swollen, but cells bursting is prevented by the cell wall.

25. Osmoregulation – in animals • Because animal cells have no cell wall – they can burst if too much water goes into them.

26. Osmoregulation – in animals • Because animal cells have no cell wall – they can burst if too much water goes into them. • If water moves out they shrivel.

27. Osmoregulation – in animals • Because animal cells have no cell wall – they can burst if too much water goes into them. • If water moves out they shrivel. • It is very important that our blood system, kidneys, and liver keeps our cells in correct balance.

28. Osmoregulation – in animals • Because animal cells have no cell wall – they can burst if too much water goes into them. • If water moves out they shrivel. • It is very important that our blood system, kidneys, and liver keeps our cells in correct balance. • Uni-cells have _________________________ to get rid of excess water.

29. Osmoregulation

30. Osmoregulation Example. • Freshwater fish are in danger because there is a lot of water going into their bodies through osmosis – they get rid of this by peeing A LOT. • Saltwater fish – Excrete salt from special glands in their gills.