1. Diffusion and osmosis

2. Types of Cellular Transport
Passive Transport
cell doesn’t use energy
Diffusion
Facilitated Diffusion
Osmosis
Active Transport
cell does use energy
Protein Pumps
Endocytosis
Exocytosis
high
low
Weeee!!!
high
low
This is gonna be hard work!!

3. Bacon Frying…
What do you smell?
Why do you smell this?

4. Bacon Frying… Fat droplets are released into the air
steam coming off of the bacon
Causes the fat droplets (particles) to collide and disperse.
In science terms…
DIFFUSION IS OCCURING! 
The bacon fat droplets (particles) diffuse from the area of high concentration (directly above the frying pan), to areas of low concentration (the room)
Continues until equilibrium is reached
Particles equally distributed throughout the space (room)

5. Diffusion
Diffusion - Defined as the movement of particles from areas of high concentration to areas of low concentration (down the concentration gradient)
Particles spread out
Ex: Solute = perfume Solvent = the air
Low Solute Concentration
An example of diffusion in the air and also in an agar dish are good to go over here.
High Solute Concentration

6. Diffusion

7. Diffusion rate (how fast it occurs) depends on:
1. Size- smaller molecules move more easily
2. Concentration- high concentration = faster spread
Ex: The more bacon you have (=more fat droplets released), the faster the smell will spread throughout the room
3. Temperature- high temps speed up the process
Which will cause the smell to disperse faster?
Cold bacon in a frying pan and the stove is OFF OR
Bacon in a frying pan and the stove in ON

8. What is a semi-permeable membrane?
A membrane that allows certain molecules to pass through it by diffusion or osmosis
Think about a Ping-Pong net..
Which would pass through?

9. Osmosis Diffusion that involves water.
Movement of water across a semi-permeable membrane

10. Cell membranes are semi-permeable
Water and some gases move through the membrane easily, while larger molecules like proteins and sugars do not.
Cells must regulate- molecules move from internal environment to external environment (and vice versa) so that both environments have equal concentrations.
Animation: How Osmosis Works

11. Why do your fingers “shrivel–up” when you are in the water?
Osmosis
Diffusion that involves water.
Movement of water across a semi-permeable membrane
Water moves from areas of low solute to areas of high solute
Why do your fingers “shrivel–up” when you are in the water?

13. Effects of Osmosis on Life
Osmosis- diffusion of water through a selectively permeable membrane.
There are 3 types of solutions (=Tonicity)
1.) Isotonic
2.) Hypertonic
3.) Hypotonic

14. WATCH VIDEO OF BLOOD IN AN ISOTONIC SOLUTION
Solutions that contain the same concentration of solutes as the cytoplasm are called isotonic (or normal saline) solutions.
There is no net movement of water either into or out of the cell.
Cells maintain their normal shape.

15. Osmosis Animations for isotonic, hypertonic, and hypotonic solutions
Isotonic Solution
Isotonic The concentration of solutes in the external solution is equal to the concentration of solutes inside the cell.
Result Water moves equally in both directions and the cell remains same size! (Dynamic Equilibrium)

16. WATCH VIDEO OF NORMAL RBCs SUBJECTED TO A HYPERTONIC SOLUTION
A hypertonic solution is a solution that contains more solutes than the cytoplasm of the cell. (hyper)
Has less water than the cell and
water moves out of the cell.
The cells shrink.

17. Osmosis Animations for isotonic, hypertonic, and hypotonic solutions
Hypertonic Solution
Hypertonic: The solution has a higher concentration of solutes and a lower concentration of water than inside the cell. (High solute; Low water)
shrinks
Result: Water moves from inside the cell into the solution: Cell shrinks (Plasmolysis/crenation)!

18. WATCH VIDEO OF CRENATED RBCs SUBJECTED TO A HYPOTONIC SOLUTION
A hypotonic solution contains less solute (thus, more water) than the cytoplasm of the cells.
The water will move into the cells resulting in the swelling and lysis of the cells. 

19. Osmosis Animations for isotonic, hypertonic, and hypotonic solutions
Hypotonic: The solution has a lower concentration of solutes and a higher concentration of water than inside the cell. (Low solute; High water)
Result: Water moves from the solution to inside the cell): Cell Swells and bursts open (cytolysis)!

20. Let’s take a closer look!
U04L06/rbc.html

21. B C A What type of solution are these cells in? Hypertonic Isotonic
Hypotonic

22. Tonicity Used to compare different solutions
Hypertonic- higher solute concentration relative to another
*think hyperactive
Hypotonic- lower solute concentration relative to another
*think hypothermia
Isotonic- equal solute concentrations between two solutions

23. Cell in Isotonic Solution
The Plasma Membrane
4/15/2017
Cell in Isotonic Solution
ENVIRONMENT
10% NaCL 90% H2O
CELL
NO NET MOVEMENT
10% NaCL
90% H2O
The cell is at _______________.
equilibrium
What is the direction of water movement?
G. Podgorski, Biol. 1010

24. Cell in Hypotonic Solution
The Plasma Membrane
4/15/2017
Cell in Hypotonic Solution
10% NaCL 90% H2O
CELL
20% NaCL
80% H2O
What is the direction of water movement??
G. Podgorski, Biol. 1010

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

26. Cells in Solutions The Plasma Membrane 4/15/2017
G. Podgorski, Biol. 1010

27. NO NET MOVEMENT OF H2O (equal amounts entering & leaving)
The Plasma Membrane
4/15/2017
Isotonic Solution
Hypotonic Solution
Hypertonic Solution
NO NET MOVEMENT OF H2O (equal amounts entering & leaving)
CYTOLYSIS
PLASMOLYSIS
G. Podgorski, Biol. 1010

28. Cytolysis & Plasmolysis
The Plasma Membrane
4/15/2017
Cytolysis & Plasmolysis
Cytolysis
Plasmolysis
G. Podgorski, Biol. 1010

29. Osmosis in Red Blood Cells
The Plasma Membrane
4/15/2017
Osmosis in Red Blood Cells
Isotonic
Hypertonic
Hypotonic
G. Podgorski, Biol. 1010

30. What Happens to Blood Cells?