1. Cell Membrane

2. Cell Membrane Phospholipid bilayer--two layers of phospholipid sheets.
polar head --hydrophilic (water loving)
non-polar--hydrophobic tail
Like a bubble made of floating buoys.

3. Fluid Mosaic The membrane is permeable
Protein and carbohydrates embedded in membrane
Proteins act as receptors
Carbohydrates can be cell identification tag.

4. Traversing the cell membrane
Pair and share:
What substances must get into or out of the cell?
Some possible answers: carbon compounds (protein, carb, lipid), waste, oxygen, CO2, salts, minerals, water

5. Diffusion
Solutes move from high concentration to low concentration, until they reach equilibrium.

6. OSMOSIS Special type of diffusion “Water moves toward salt (solute)”
Diffusion of water through a selectively permeable membrane.
What would happen to the water in cells if the blood becomes dehydrated (more salty)?

7. How substances traverse the membrane
Cell Transport
Diffusion
Simple Diffusion
Facilitated Diffusion
Active Transport-Req’s Energy
Pumps (Sodium Potassium Pump)
Endocytosis/ Exocytosis
Osmosis

8. ANIMATIONS OF ALL PROCESSES
Membrane Transport Graphic Organizer

9. BULK TRANSPORT EXOCYTOSIS/ ENDOCYTOSIS COOLEST ANIMATION EVER
WHAT CELL PARTS DO YOU NOTICE?
COOL ANIMATION
CLICK ON 1.80 EXO/ENDOCYTOSIS

10. Tonicity These terms are always used in comparison
Draw a representation of each
Isotonic solution
Hypertonic solution
Hypotonic solution

11. Lower concentration of solute (sugar) Higher concentration of solute
Figure 7.14
Lower concentration of solute (sugar)
Higher concentration of solute
Same concentration of solute
Sugar molecule
H2O
Selectively permeable membrane
Figure 7.14 Osmosis.
Osmosis 11

12. Work it Out What would happen to a blood cell in… Blood Plasma?
Pure water?
Highly Saline (salty) solution?

13. Hypotonic solution Isotonic solution Hypertonic solution
Figure 7.15
Hypotonic solution
Isotonic solution
Hypertonic solution
(a) Animal cell
H2O
H2O
H2O
H2O
Lysed
Normal
Shriveled
H2O
Cell wall
H2O
H2O
H2O
(b) Plant cell
Figure 7.15 The water balance of living cells.
Turgid (normal)
Flaccid
Plasmolyzed
Osmosis 13

14. Work it Out What would happen to a blood cell in…
Blood? Stays the same
Pure water? Swells and bursts (lyse)
Salt water? Shrinks --water leaves (crenate)

15. Watch the Process See animations on Memory Stick Diffusion Osmosis
Cell Transport