1. Membrane Lipid = Phospholipid
YOU REMEMBER THE PHOSPHOLIPID RIGHT?
Polar Head
Two Nonpolar Tails

2. Let’s take another look:
HYDROPHILIC – loves water
HYDROPHOBIC – fears water

3. A Bilayer!!!!
HYDROPHILIC
HYDROPHOBIC
HYDROPHILIC
Phospholipid Bilayer – two rows of phospholipids that surround every cell.

4. Put It All Together
Remember: The membrane is made of 3 major molecules, not only LIPIDS!

5. “Fluid Mosaic” Model

6. One difference is the membrane lipids!
Unlike other organisms, archean cells use ether linked (-OH : -OH) lipids in their membranes. Also, the “tails” are funky.
Take home: archea have weird membrane lipids

7. Different membranes for different environments

8. Membrane fingerprints
Long chains are more like butter (for high temps)
Short chains are like oil (cold temps)

9. The wonderful world of lipid chemistry

10. The Basics are as easy as 1. hydrophilic heads 2. hydrophobic tails 3
The Basics are as easy as 1. hydrophilic heads 2. hydrophobic tails 3. phospholipid bilayer!

11. Wrap Up Cell membrane structure: phospholipid bilayer
Cell membrane function: selective permeability controls what enters / exits cell
Time for a video? Inner Life of A Cell
Harvard U BioVisions computer modeling lab.