1. Diffusion Through a Membrane Lab
S G I G I S S G I G I S G I S I S G I S I S I S

3. Where is the water moving?
The water is moving out of the cell.
Why?
Remember where ever salt is water follows!
Salt
SALT

4. Where is the water moving?
Water is moving out of the cell.
Why?
Because where ever salt is water follows.

5. Light blue = Salt Dark blue = water

6. There is a lot of salt out side the cell what will happen? Why?

7. What will happen if there is a lot of salt inside the cell?

8. Red Onion Cells Normal In Salt Water
What happened to the cytoplasm and cell membrane?

9. Making The Cell What is located inside the cell in the beginning?
Starch, Glucose, and Water.

10. This is what the experiment looks like in the beginning
Water and Starch Indicator Solution are located on the outside of the cell.
Starch and Glucose are located inside the cells.

11. What’s happening after the 1st 10 minutes?
The cell is starting to turn blue black
Why?
Because Starch Indicator solution is moving across the membrane.

12. Is This The Final or Initial State?

13. Label The Contents Of Your Cells
Initial State
Final State
H20, Glucose, & Starch Indicator Solution
H20 and Starch Indicator Solution
Starch and Glucose
Glucose, Starch, and Starch Indicator Solution

15. 7) In the initial state diagram below, Starch Indicator Solution is indicted by the letters “I”. The letters “S” Stand for Starch and G for Glucose. Indicate the areas where each of these molecules are located in both diagrams.
I I I I I I
I G I G I G I G I G I
S G S G S G S S G G S G
G S S G G S
S G I G I S S G I G I S G I S I S G I S I S I S
I G I G I G I G I
I I I I I I I I I I I I

16. Question #1
During the lab, one group of students messed up. They poured the starch indicator solution into the cell and filled the beaker with starch and glucose solution. State what their results would look like.
The outside of the cell would turn blue black instead of the inside of the cell.

17. What Went Wrong?

18. Question #2 Normal plant cell Plant cell in salt environment.
The salt would damage or kill the plants. The salt environment would cause water to move out of the plant cell
Normal plant cell

19. Question # 3
When a person is given an I.V., the fluid has a little salt in it just like our blood.
Explain how the use of distilled water in place of saline solution would up set homeostasis.

20. Question # 4
Homeostasis would be upset because their would be more salt inside a cell then outside a cell. The water would move into the cell causing it to burst.

21. Question # 5
Fresh water fish have a contractile vacuole which pump out extra water. Explain why once celled organism in salt water would not need a contractile vacuole?
Contractile vacuoles are of no value to salt water organisms because there is no excess water to be removed.
Salt Water
Fresh Water

22. Question #6 Why does eating popcorn make you thirsty?
Popcorn is very salty and may cause water to leave the cells of your mouth and through due to diffusion. This makes a person thirsty.

23. 6) Why is the digestion of starch to glucose necessary?
Starch is big and must be broken down into glucose so it can diffuse across a cell membrane. Glucose is small enough to diffuse across a cell membrane.
Glucose
Starch (carbohydrate)

24. Your homework Is to finish your lab
Your homework Is to finish your lab! If it is not done it will be a Zero. No excuses!
The Mad Scientist