1. Diffusion Lab
Subtitle

2. Cell Membrane Structure Function Phospholipid bilayer
SEMI or selectively PERMIABLE
Control what enters and exits the cell
Protective barrier surrounding the cell

3. Cell Membrane Transport
Active transport
Passive Transport
Moves molecules from low to high concentration
Requires energy (ATP)
Ex: Vesicle transport, pumps
Moves molecules from high to low concentration
No energy required
Ex: diffusion and osmosis

4. Passive Transport: Diffusion
molecules move from a region of high concentration to a region of low concentration
Movement is DOWN a Concentration Gradient
Does not require energy
Passive transport
Molecules move through phospholipid bilayer
Like going down a slide; it’s hard to climb up, but easy to slide down

5. Facilitated Diffusion
Not all molecules can easily cross the cell membrane on their own
Larger molecules diffuse across the membrane WITHOUT energy by moving through channel proteins
Still passive transport - NO energy required
Note: This is still considered passive transport since movement is down the concentration gradient

6. Diffusion lab
The beaker contains an orange solution of iodine and water. Notice that the liquid is clear, not cloudy.

7. Diffusion Lab
Our “cell” (ziplock with starch solution) will be placed in the iodine solution and allowed to sit.
PREDICT: what do you expect will happen?

8. Diffusion Lab
How to be a CHAMPion:
C- level 2 voice with your group
H- ask your group members before me
A- complete diffusion lab
M- remain at your assigned lab table, DO NOT move around between groups or you will be asked to sit down and receive a 0 for the lab.
P- work with your group, record your finding and answer questions on your own lab sheet you will NOT be taking this home
SUCCESS
Working in your assigned groups, you will complete the Diffusion lab.

9. Diffusion lab
After being allowed to sit, the “cell” is removed from the solution.
The starch solution has turned purple.
The iodine solution appears unchanged (notice that there is no cloudiness to the solution)

10. Flow chart
Create a flow chart comparing Passive and Active transport

11. Semantic Mapping Cell membrane Active transport Phospholipid bilayer
Osmosis
Control passage of material
Passive transport
Protein channel
Endocytosis and exocytosis
Vesicle transport
Cholesterol
Diffusion
Facilitated diffusion
Example

12. Exit ticket
Clear you desk except for your DO NOW

13. 1. A beaker is divided into two halves, A & B, by a membrane that is freely permeable to the water and NaCl but not to protein. Side A is half-filled with a solution of 8% protein, while side B is half filled with a 2% protein solution. Predict what would happen to side A after a few hours.
The number of protein molecules has increased.
The number of water molecules has decreased.
The number of water molecules has increased.
The percentage of water has decreased.

14. The cell membrane of the red blood cell will allow water, oxygen, and carbon dioxide to pass via osmosis. However, other substances are blocked from entering. What is this membrane called?
Perforated
Permeable
non-conductive
semi-permeable

15. Look at the diagram of a cross-section of a cell membrane below
Look at the diagram of a cross-section of a cell membrane below. The cell membrane controls movement of materials into and out of the cell. The following particles are moving from high concentration to low concentration and are using a carrier protein. How would you describe this type of movement across the membrane?
a. simple osmosis
b. active transport
c. simple diffusion
d. facilitated diffusion

16. 4. Look at the cross section of a cell membrane of a eukaryotic cell
4. Look at the cross section of a cell membrane of a eukaryotic cell. H+ ions are being pumped from a low concentration to a high concentration. How do you describe this type of transport across the cell membrane?
a. active transport
b. passive transport
c. facilitated diffusion
d. co-transport