1. Cell Membrane Maintains homeostasis by regulating the movement of molecules in and out of the cell

2. Why is the plasma membrane described as “fluid mosaic”?

3. Fluid Mosaic Model Fluid
Polar heads are orientated to the aqueous solution (inside and outside of cell)
Non polar tails are orientated towards one another
Mosaic
Integral proteins are embedded to form a mosaic

5. Membrane Proteins Channel Proteins (transport)
Carrier Proteins (transport)
Receptor Proteins (signal transduction)
Cell Recognition Proteins (glycoproteins)
Enzymatic Proteins (internal active sites)
Intercellular Joining (cell junctions)
Attachment for Cytoskeleton

7. Membrane Permeability
Impermeable
Permeable
Differentially/Selectively Permeable

8. Terms to know Osmotic pressure Turgor Pressure Tonicity Isotonic
Hypotonic
Hypertonic
Plasmolysis
Creanation

9. Methods of Transport Across The Cell Membrane
Passive Transport

11. Molecules Using Diffusion
Lipids (steroids)
O2 & CO2
Through phospholipids bilayer

12. Factors Affecting Rates of Diffusion
Temperature increase
Increased concentration gradient
Increased membrane permeability
Smaller molecule size

13. Osmosis
Diffusion of water through a semi permeable membrane (channel proteins)

14. Problems to Solve Which side is hypertonic? Which side is hypotonic?
Which way will water move in 30 minutes?
After 30 minutes which side has a higher concentration?
If the membrane is impermeable to salt but permeable to glucose describe the movement of solutes and water after 2 hours.

16. This happens in plants….what is it?

17. Facilitated Transport/Diffusion
Movement of molecules along the concentration gradient with the aid of carrier proteins
Example: amino acids, glucose

19. Active Transport
Movement of molecules against the concentration gradient using carrier proteins and ATP
Example: Na+, K+ and iodine

20. Types of Active Transport for Macromolecules

21. Types of Active Transport for Macromolecules

22. Animation Review