1. What is diffusion? Movement of a molecule from…….
What is the concentration gradient?
From high to low concentration

2. Osmosis?
Movement of water from high to low concentration

3. Does it take Energy?
NO! diffusion and osmosis are passive transport, and so do not use energy
Some forms of molecule movement do take energy…. We call this active transport

4. Phagocytosis Active transport Engulfing food using cell membrane
Pinocytosis is little bitty “bites”(or spitting out little bitty pieces)

5. 1. What does the tubing represent?
Cell membrane
2. What is inside the tubing?
Starch & glucose

6. 3. What did we add to make the liquid outside the “cell” amber colored?
Starch indicator (iodine)

7. 4. Why does the inside of the “cell” turn purple or black?
High s.i.conc.
Low s.i. conc.
Starch indicator diffused into the tubing
Passive or active transport?
Permeable or impermeable to starch?

8. 5. How do we know that starch did not move from the inside to the outside?
No color change outside

9. 6. How can we find out if glucose moved into the beaker?
Glucose (high conc.)
Do a glucose indicator test using the fluid in the beaker

10. 7. After placing 10 drops of the amber solution into a test tube, what do we add to it?
Glucose indicator

11. 8. After adding the glucose indicator solution (blue) what do we do with the test tube?
Heat it

12. 9. If there is glucose in the solution, what will happen to the blue color after heating the tube for 2 minutes?
The color changes

13. 10. The blue color changed to orange
10. The blue color changed to orange. This means that what substance is in the test tube?
glucose

14. starch
glucose
C6H12O6
11. Glucose indicator solution was added to these test tubes, and then the tubes were heated. Which will change color?

15. Were you right?

16. How did the onion cell respond to distilled water?
Cytoplasm
Cell Membrane
Cell Wall
What do you notice about the cytoplasm?

17. How did the red onion respond to salt water (NaCl H2O)?
Cytoplasm
Cell Membrane
Cell Wall
What do you notice about the cytoplasm?

18. Why does the cytoplasm get smaller in salt water?
DISTILLED (concentration of water is higher outside the cell) WATER moves INTO THE CELL.
In SALT WATER: (conc. of water is higher inside the cell) Water diffuses OUT OF THE CELL.

19. OSMOSIS VIDEO

20. How does this relate to YOU?
CHEEK CELLS