1. Warm up
Please get out your Labs and complete the graph and questions on the back. Remember this lab is going to be turned as a product grade so try your best!

2. Movement through cell membranes

3. Diffusion Example: exchange of oxygen and carbon dioxide in lungs
Molecules or ions moving from areas of higher concentration to lower concentration
Difference in concentration is the concentration gradient
Concentrations are equal = equilibrium

4. Diffusion in & out of a cell
the cell membrane is permeable to that substance (fat soluble such as 02 and CO2)
2. concentration gradient exists such that the substance is at a higher concentration either outside or inside the cell.

5. Water molecules diffuse from higher water concentrations to lower water concentrations
In solutions: higher concentration of solute, lower concentration of water; lower concentration of solute, higher concentration of water.
Greater the concentration of solute (proteins), lower water concentration, greater osmotic pressure.
Lower the concentration of solute (proteins), higher water concentration, lower osmotic pressure

6. Osmosis
Which way is the water moving across the membrane?

7. Hypertonic
When fluid outside the cell has greater pressure than fluid inside the cell – water leaves cell
example: salt water outside our potato is a hypotonic environment
If you are stranded on an island why wouldn’t you want to drink the water around you?

8. Hypotonic
When intracellular fluid has greater pressure than extracellular – water enters cell
example distilled water out side our potato is a hypotonic environment
If an animal cell is over exposed it will burst.
Example: Over hydration by drug user

9. Isotonic
When inside the cell and outside the cell are the same = isotonic

10. NO NET MOVEMENT OF H2O (equal amounts entering & leaving)
The Plasma Membrane
4/26/2017
Isotonic Solution
Hypotonic Solution
Hypertonic Solution
NO NET MOVEMENT OF H2O (equal amounts entering & leaving)
Water enters cell- can cause it to burst
Water leaves cell until it “deflates” 10
G. Podgorski, Biol. 1010 10

11. Cell in Isotonic Solution
The Plasma Membrane
4/26/2017
Cell in Isotonic Solution
10% NaCL 90% H2O
ENVIRONMENT
CELL
NO NET MOVEMENT
10% NaCL
90% H2O
What is the direction of water movement?
equilibrium
The cell is at _______________. 11
G. Podgorski, Biol. 1010 11

12. Cell in Hypotonic Solution
The Plasma Membrane
4/26/2017
Cell in Hypotonic Solution
10% NaCL 90% H2O
CELL
H2O
20% NaCL
80% H2O
What is the direction of water movement?
What is the direction of water movement? 12
Water moves into the cell
G. Podgorski, Biol. 1010 12

13. Cell in Hypertonic Solution
The Plasma Membrane
4/26/2017
Cell in Hypertonic Solution
15% NaCL 85% H2O
ENVIRONMENT
CELL
H2O
5% NaCL
95% H2O
What is the direction of water movement?
What is the direction of water movement? 13
G. Podgorski, Biol. 1010 13

14. Pass out practice problems
Stop!
Pass out practice problems

15. Warm up
Why don’t you want to drink salt water? What kind of environment would drinking salt water create in your body? What would happen to your cells?
If you have 95% water and 5% solute on the inside of a cell and 80% water 20% on the out side which way will the water move?

16. Three Types of Transport:
Passive Transport (no energy needed)
Includes: Diffusion, Osmosis (a type of diffusion), and Facilitated Diffusion
2. Active transport (energy required) 16

17. Three Forms of Transport Across the Membrane
The Plasma Membrane
Three Forms of Transport Across the Membrane
4/26/2017 17
G. Podgorski, Biol. 1010 17

18. Passive Transport Simple Diffusion Doesn’t require energy
The Plasma Membrane
4/26/2017
Passive Transport
Simple Diffusion
Doesn’t require energy
Molecules move from high to low concentration 18
G. Podgorski, Biol. 1010 18

19. Facilitated diffusion
The Plasma Membrane
4/26/2017
Passive Transport
Facilitated diffusion
Doesn’t require energy
Uses transport proteins to move high to low concentration
Examples: Glucose or amino acids moving from blood into a cell. 19
G. Podgorski, Biol. 1010 19

20. Facilitated Diffusion
The Plasma Membrane
4/26/2017
Facilitated Diffusion
Molecules will move through the pores in Protein Channel
copyright cmassengale 20
G. Podgorski, Biol. 1010 20

21. Active Transport Requires energy or ATP
The Plasma Membrane
4/26/2017
Active Transport
Requires energy or ATP
Moves materials from LOW to HIGH concentration
AGAINST concentration gradient 21
G. Podgorski, Biol. 1010 21

22. Active transport

23. Active Transport Similar to facilitated diffusion
Differs in that particles are moving from areas of low concentration to high concentration
Carrier proteins also called pumps
Examples: sugars, amino acids; sodium, potassium, calcium, and hydrogen ions
Also absorb nutrients into cells of the intestinal walls

24. Exocytosis- moving things out.
The Plasma Membrane
Moving the “Big Stuff”
4/26/2017
Exocytosis- moving things out.
Molecules are moved out of the cell by vesicles that fuse with the plasma membrane.
This is how many hormones are secreted and how nerve cells communicate with one another. 24
G. Podgorski, Biol. 1010 24

25. The Plasma Membrane
4/26/2017
REVIEW QUESTIONS
How does osmosis or Diffusion play a role in the human body?
What is the main difference between Passive transport and Active transport?
What is endocytosis and exocytosis?
What happens if a red blood cell is in a hypertonic solution? Hypotonic? Isotonic? 25
G. Podgorski, Biol. 1010 25