1. Cell Membrane Transport Notes
April 24, 2017

2. I.) Types of Cell Membrane Transport
There are 2 types of cell membrane transport:
Passive Transport
Things flow from
High to low
Active Transport
Low to high

3. Passive & Active Transport

4. II.) Passive Transport Diffusion
Definition: The movement of particles from areas of high concentration to low concentration

5. Equilibrium
Continuous movement of particles, but no change in concentration
When is equilibrium reached when discussing cell membrane transport?
When the concentrations of particles are the same on both sides

6. Facilitated Diffusion
Particles flow from high concentration to low concentration but this time they need the help of proteins to get through the cell membrane.

7. Passive transport (cont.)
Osmosis
The diffusion of water across a selectively permeable membrane
Important in maintaining cell homeostasis
Water flows to side of membrane where the water concentration is lower until equilibrium is reached

8. Osmosis (cont.)
Osmosis is controlled by the amount of solutes on either side of a membrane

9. Remember, this is important, Osmosis deals with what?
The movement of particles
The movement of glucose
The movement of water
The movement of lipids 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

10. Osmosis – Types of Solutions
When dealing with osmosis, water can either move into the cell or out of it.
We describe the solutions that cells are in as either hypotonic, isotonic, or hypertonic.
90%
What are the concentrations?
40%

11. Isotonic Solution
Isotonic solution – Concentration of solute is the same in the cell and the area around the cell.

12. Isotonic solution

13. Hypotonic Solution
Hypotonic Solution – Concentration of solute is lower in the solution than in the cell.
Where is water going to move in order to reach equilibrium (Equal concentrations)?
Inside the cell

14. Hypotonic solutions
Since water moves into the cell the cell can explode
So, Hypotonic solution, low concentration of solute, cell can explode

15. Plant & animal cells in a hypotonic solution

16. Hypertonic Solution
Hypertonic solution – concentration of solute is higher in the solution than in the cell.
Where is water going to move in order to reach equilibrium (Equal concentrations)?
Outside the cell

17. Hypertonic solutions
Since water moves out of the cell the cell will shrink
So, Hypertonic solution, high concentration of solute, cell will shrink

18. Plant & animals cells in a Hypertonic Solution

19. The following diagram demonstrates what type of solution?
= solute
Hypotonic
Isotonic
Hypertonic 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

20. In the following diagram which way is water going to move?
= solute
Inside the cell
Outside of the cell
Both 1 and 2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

21. The following diagram demonstrates what type of solution?
= solute
Hypotonic
Isotonic
Hypertonic 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

22. In the following diagram which way is water going to move?
= solute
Inside the cell
Outside of the cell
Both 1 and 2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

23. Active Transport
Molecules move from low concentration to high concentration
Requires energy….why?

24. Other membrane transport activities that require energy
Endocytosis
Engulfing of large particles or liquids from outside the cell

25. 2 types of Endocytosis Phagocytosis Pinocytosis
Engulfing of large particles
from outside the cell
Pinocytosis
Engulfing of
liquids from
outside the cell

26. Other membrane transport activities that require energy
Exocytosis
Release of large particles or liquids from inside the cell
Outside the cell
Inside the cell

27. This diagram is an example of what membrane transport?
Diffusion
Facilitated diffusion
Endocytosis
Exocytosis 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

28. This diagram is an example of what membrane transport?
Diffusion
Facilitated diffusion
Endocytosis
Exocytosis 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30