1. Passive Transport

2. Passive Transport
Passive transport: Cell spends no energy (ATP) to move molecules
Does this kayaker need to spend his energy in order to move?

3. Passive Transport
Passive transport: Cell expends no energy (ATP) to move the molecules
Molecules move from a high to low concentration
Down their concentration gradient
Examples:
Diffusion
Osmosis
Facilitated diffusion

4. Diffusion: Movement of molecules from an area of high to low concentration
Movement continues until equilibrium is reached
Equilibrium: even balance of molecules
This is how many molecules move into and out of cells

5. Movement continues until equilibrium is reached
Will oxygen mostly enter or exit this cell? O2 O2 O2 O2 O2 O2 O2 O2 O2 O2 O2
Diffusion: Movement of molecules from an area of high to low concentration
Movement continues until equilibrium is reached
Equilibrium: even balance of molecules
This is how many molecules move into and out of cells

6. Diffusion Video Clip

7. O2
The woman inhales a breath of oxygen O2 O2 O2

8. O2 O2 O2 O2 O2 O2
The oxygen spreads into the womans lungs

9. O2 O2 O2 O2 O2 O2
The oxygen fills the air sacs (alveoli) located in her lungs

10. Due to diffusion, the oxygen will spread from her lungs… into her blood
Where is the HIGH oxygen concentration? O2 O2 O2 O2 O2 O2
Where is the LOW oxygen concentration?

11. The heart pumps this oxygen-rich blood around her body

12. O2 O2 O2 O2 O2 O2
Cell X needs oxygen just like all cells. But cell X is not in direct contact with the blood and oxygen. So how does cell X get oxygen?

13. Where is the HIGH oxygen concentration?
Diffusion: movement of molecules from a high to low concentration
Where is the HIGH oxygen concentration?
Where is the LOW oxygen concentration? O2 O2 O2 O2 O2 O2
Cell X (and all other cells) gets oxygen through the process of diffusion!

14. The reverse process is true w/ carbon dioxide
The reverse process is true w/ carbon dioxide. Over time, CO2 waste builds up in cells. Too much is fatal. It must be removed.
CO2
CO2
CO2
CO2
CO2
CO2
CO2
CO2
CO2

15. Where is the HIGH carbon dioxide concentration?
Where is the LOW carbon dioxide concentration?
CO2
CO2
CO2
CO2
CO2
CO2
CO2
CO2
CO2
CO2 diffuses from the cells (high concentration) and into the blood stream (low concentration)

16. The heart pumps the CO2 rich blood back to the lungs.

17. CO2
Where is the HIGH carbon dioxide concentration?
CO2
CO2
CO2
CO2
CO2
CO2 diffuses into the air sacs (alveoli)
CO2
CO2
CO2

18. The woman begins to exhale
CO2
CO2
CO2
CO2
CO2
CO2

19. The diaphragm muscle pushes the CO2 out of the lungs

20. CO2 is expelled… the process repeats with every breath!

21. Osmosis Defined: Diffusion of water from a high to low concentration
High H2O concentration
Less solutes
Ex: Distilled water
Distilled water
(no solutes)
Cell

22. Osmosis Defined: Diffusion of water from a high to low concentration
High H2O concentration
Less solutes
Ex: Distilled water
Low H2O concentration
More solutes
Ex: Salt water
Salt water
(high solutes)
Cell

23. Quick Lab Activity One potato slice has been placed inside salt water.
One potato slice has been placed inside distilled water.
Salt water
Distilled water
Potato slice
Potato slice
Results: The potato slice lost weight
Results: The potato slice gained weight

24. Where is the high water concentration in the salt water experiment?
Distilled water
1 minute: Discuss with your neighbor
Potato slice
Potato slice
Results: The potato slice lost weight
Results: The potato slice gained weight
Where is the high water concentration in the salt water experiment?
Low water concentration?
3) Where is the high water concentration in the distilled water experiment?
4) Low water concentration?

25. Where is the high water concentration in the salt water experiment?
Distilled water
Low
water
High
water
water
Results: The potato slice lost weight
Results: The potato slice gained weight
Where is the high water concentration in the salt water experiment?
Low water concentration?
3) Where is the high water concentration in the distilled water experiment?
4) Low water concentration?

26. Where is the high water concentration in the salt water experiment?
Distilled water
High
Low
water
High
Low
water
water
Results: The potato slice lost weight
Results: The potato slice gained weight
Where is the high water concentration in the salt water experiment?
Low water concentration?
3) Where is the high water concentration in the distilled water experiment?
4) Low water concentration?

27. 5) Why did the salt water potato lose weight?
Distilled water
30 seconds: Discuss with your neighbor
High
Low
High
Low
Results: The potato slice lost weight
Results: The potato slice gained weight
5) Why did the salt water potato lose weight?
6) Why did the distilled water potato gain weight?
Water diffused out of the potato.
Water diffused into the potato.

28. Dots represent dissolved particles (not water molecules)
Isotonic
Environment with an equal balance of solutes
Hypertonic
Environment with more solutes outside a cell
Hypotonic
Environment with more solutes inside a cell
Low water
High water
Dots represent dissolved particles (not water molecules)

29. Facilitated Diffusion
glucose
glucose
Facilitated Diffusion
glucose
Protein channel
Facilitate means “to help”
Defined: Larger molecules enter/exit with the help of protein channels in the plasma membrane
No energy (ATP) used
glucose

30. Facilitated Diffusion

31. Kobe Kuiz
1) In which direction does diffusion occur? 2) Across which part of the cell does diffusion mostly occur? 3) Which molecule of energy is not required during passive transport? 4) True or False: More solutes creates less concentrated water. 5) Which chemical is involved in osmosis? 6) Examine the picture. If the dots are solutes, where is the high solute concentration? 7) Examine the picture. If the dots are water molecules, where is the low water concentration? 8) Examine the picture. If the dots are water molecules, which way will osmosis occur? 9) Examine the picture. If the dots are solute molecules, which way will osmosis occur?

32. Kobe Kuiz
10) Place the steps of oxygen flow in the correct order from start to finish. A – Oxygen diffuses into your cells B – Your heart pumps oxygen-rich blood around your body C – Oxygen moves into your lungs D – Oxygen gas is inhaled E – Oxygen diffuses from your lungs into your blood 11) Place the steps of CO2 flow in the correct order from start to finish. A – Your heart pumps CO2-rich blood towards your lungs B – CO2 waste is created by every cell C – CO2 is pushed out of your lungs and out of your mouth D – CO2 diffuses from your blood into your lungs E – CO2 diffuses from your cells into your blood