1. Dynamic Cells Membrane Properties Transport Across Cell Membranes
Cell Size and Functions

2. Membrane Properties
Membrane Structure
Membrane Function

3. Cell membranes are phospholipid bilayers

4. What are phospholipids?

5. Phospholipids self assemble into different structures because their hydrophobic and hydrophilic ends repel each other

6. What’s a Phospholipid Bilayer?
2 layers of phospholipids

7. Each layer has:
a hydrophilic phosphate end (hydro = water, philic = loving)
and a hydrophobic lipid tail (phobic = fears, repels)

8. Cell membranes are like mosaics
Lots of phospholipid tiles with protein, carbohydrate chain and cholesterol tiles thrown in!

9. Why the different tiles?

10. Membranes are responsible for an incredible number of things!

11. carbohydrate chains are for cell to cell communication.

12. Proteins are crucial for the transport of substances in and out of the cell

13. Membrane Proteins can be peripheral (on surface) or integral (spans the membrane)

14. Cholesterol maintains proper membrane flexibility, and also is crucial for cell signaling and nerve conduction.

15. Cholesterol is not just a bad guy!

16. Fluid Mosaic Model
Cell membranes are constantly MOVING and CHANGING.

17. Gives cell flexibility, movement RBC membrane
Fluid Mosaic Model
Gives cell flexibility, movement RBC membrane

18. Changes the positions of the proteins, lipids and carbohydrates embedded in the membrane, changing the “mosaic” to meet changing needs

19. 3 Functions of the Cell Membrane
1. Barrier – keeps “baddies out, cell organelles in
Bacteria pollution resistant bacteria

20. 3 Functions of the Cell Membrane
Organization – membranes surround and package materials in vesicles,
lysosomes E.R.

21. 2. Organization – membranes
2. Organization – membranes organize complex reactions like photosynthesis and cellular respiration

22. 3. Selective Filter – SEMI-PERMEABLE – only allows certain substances in or out
Regulated by particle size and by selective transport by membrane proteins

23. Clips http://www.youtube.com/watch?v=Rl5Em UQdkuI&feature=fvwrel
fluid mosaic model
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how a hormone communicates to the cell through the membrane