1. Passive and Active Transport
Cellular Movement
Passive and Active Transport

2. Passive Transport
Does NOT require ENERGY to move particles into or out of a cell
Movement of particles from HIGHER concentration to LOWER concentration
DIFFUSION – movement of particles
OSMOSIS – movement of water

3. DIFFUSION
The process in which molecules move from areas of HIGH concentration to areas of LOW concentration

4. DIFFUSION
Example: Smell of baking cookies from the oven moving through the house.

5. OSMOSIS
The diffusion of water molecules through a membrane

6. OSMOSIS
Movement of WATER from a HIGHER concentration to a LOWER concentration
Example: Plant taking in water during a rainy day.

7. Let’s Practice…

8. Let’s Practice…
The concentration of oxygen particles inside a cell is 45 percent and outside the cell is 30 percent. What will most likely happen?

9. Let’s Practice…
The concentration of water molecules inside a cell is 80 percent and outside the cell is 25 percent. What will most likely happen?

10. Let’s Practice…
The concentration of hydrogen particles inside a cell is 33 percent and outside the cell is 62 percent. What will most likely happen?

11. Equilibrium In all cases, cells want EQUILIBRIUM!
Too much (or too little) of a good thing is BAD for the cell!

12. When do the molecules stop moving?
EQUILIBRIUM = molecules are evenly distributed

13. Active Transport
Requires ATP ENERGY to move particles into or out of cell
Movement of particles from LOWER concentration to HIGHER concentration
Endocytosis
Exocytosis

14. ENDOCYTOSIS
Cell membrane encloses a vesicle filled with particles and absorbs it, BRINGING IT INTO the cell

15. EXOCYTOSIS
Cell membrane encloses a vesicle filled with particles and PUSHES IT OUT of the cell

17. Active Transport Example:
A person trying to squeeze into an already crowded elevator!
It takes ENERGY to do so!

18. What happens to cells when put in salt water?
This is why you do not want to drink salt water when you are lost at sea!

19. Water moves out of the cell to try to reach equilibrium
Water moves out of the cell to try to reach equilibrium. The cell dries out, shrinks, and dies!