1. Topic 3 FAQ’s

2. Why don’t humans have a cell wall?
Because we’re made up of animal cells, which do not have a cell wall!
Who does (answer to #1 on podcast)
Plants
Fungi
Bacteria
Protists

3. Diffusion #2: High concentration to low concentration
Doesn’t need membrane-NATURAL PROCESS
Doesn’t need energy either! (molecules always moving)
#3-FALSE-molcuels still move even in equilibrium

4. #4-Hypotonic LOW solute concentration outside the cell (high water)
Water will move INTO the cell
#5-This is better for plants
Why water shoots out when you bite celery/apples
Go to smartboard-ask where water will move-in, show in, show plant vs animal

5. #6 Hypertonic HIGH concentration of solute outside cell (low water)
Water moves OUT
Bad for everybody
Show on smarboard

6. #7 Isotonic EVEN concentration of solute/water
Note-water moves back and forth AT THE SAME RATE
#8-Animals do better, plants will wilt
smartboard

7. #9/10
Facilitate-to help
Facilitated diffusion-diffusion across a membrane that needs a little help, specifically:
Proteins
Still doesn’t require any
Energy!!

8. #11-Active transport
Going AGAINST concentration gradient (low to high)
Will NOT happen on its own-needs energy and proteins to help!
Think:
Active-need energy
Would rather be spread out (no energy) than close together (more energy)
Doesn’t happen as often because needs energy

9. #12-ATP
Adenosine Tri Phosphate
Cell’s immediate energy source

10. #13 ATP and Proteins
ATP’s energy is used to change the shape of the protein
Without it, wouldn’t be able to move anything from low to high (need for nervous system)
Explain na k pump as you go

11. #14 Potassium and proteins
In the sodium-potassium pump, when potassium binds, protein again changes shape

12. #15
3 ions sodium, 2 ions potassium

13. Diffusion A-Requires energy B-doesn’t require energy
A-Requires a membrane B-doesn’t require a membrane
A-High to low B-Low to high
A-Involves proteins B-Doesn’t involve proteins

14. Facilitated diffusion
A-Requires energy B-doesn’t require energy
A-Requires a membrane B-doesn’t require a membrane
A-High to low B-Low to high
A-Involves proteins B-Doesn’t involve proteins

15. Active Transport A-Requires energy B-doesn’t require energy
A-Requires a membrane B-doesn’t require a membrane
A-High to low B-Low to high
A-Involves proteins B-Doesn’t involve proteins