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

Osmosis? Movement of water from high to low concentration

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

Phagocytosis Active transport Engulfing food using cell membrane http://www.funsci.com/fun3_en/protists/exhibition.htm Pinocytosis is little bitty “bites”(or spitting out little bitty pieces)

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

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

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?

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

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

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

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

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

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

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

Were you right?

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

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

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.

OSMOSIS VIDEO http://microscopy4kids.org/webpage/pages/ideasosmisis.html

How does this relate to YOU? CHEEK CELLS