1. Cell Transport

2. The cell membrane lets thing in and out of the cell
Carbohydrates
Cholesterol
Protein Channel
Cytoskeleton
Phospholipids

3. The cell membrane is selectively permeable
This means: it selects what can come into the cell
“Semipermeable”
outside cell
inside cell aa
sugar
H2O
NH3
salt
lipid

4. Remember... Phosphate group head Fatty acid tails
hydrophilic (likes water)
Fatty acid tails
hydrophobic (hates water)
Arranged as a bilayer (bi = 2)

6. cell needs materials in & products or waste out
Cell membrane is the boundary between inside & outside…
separates cell from its environment 
Can it be an impenetrable boundary? IN
food
carbohydrates
sugars, proteins
amino acids
lipids
salts, O2, H2O
OUT
waste
ammonia
salts
CO2
H2O
products
OUT IN
cell needs materials in & products or waste out

8. How do things get through the cell membrane?
Passive Transport
Diffusion
Osmosis
Facilitated Diffusion
Active Transport

10. Diffusion Movement of solutes from high to low concentration
No energy is needed
SOLUTE
MEMBRANE

11. WATCH
The ink will diffuse in the water

12. Facilitated Diffusion
Facilitated Diffusion: Molecules need a protein channel to pass through the cell membrane, no ATP needed
Protein Channel

13. Facilitated Diffusion
Protein channel allows specific molecules to pass
Like the bouncer of a club!
No energy is needed
facilitated = with help
high
low
“The Bouncer”

14. Osmosis
Osmosis: the diffusion of water through a cell membrane

16. Concentration of water
Direction of osmosis is determined by comparing total solute concentrations
Hypertonic - more solute, less water
Hypotonic - less solute, more water
Isotonic - equal solute, equal water

18. Cell survival depends on balancing water uptake & loss

19. Active Transport
Active Transport: Molecules need a protein pump to get into cell
Uses Energy =
Goes from low to high= UP the concentration gradient
low
high
ATP
ATP
“The Doorman”

22. Endocytosis Endocytosis: taking things into the cell in vesicles
Examples: Phagocytosis and Pinocytosis
phagocytosis
pinocytosis

23. How do larger molecules get in and out of the cell?
endocytosis
phagocytosis = “cellular eating”
pinocytosis = “cellular drinking”
exocytosis

24. Exocytosis
Exocytosis: molecules exit the cell in vesicles

25. Watch & Try
_07/get_chapter_group.htm?cin=2&rg= animated_biology&at=animated_biolog y&var=animated_biology

26. Work on cell transport worksheet
Review
Work on cell transport worksheet