1. Plasma Membrane

2. Cell Membrane 1. What is the special lipid found in the plasma membrane? 2. What do you think makes up the plasma membrane?

3. The Cell Membrane

4. Main components  Phospholipids  Cholesterol  Proteins Integral Integral Peripheral Peripheral  Glycolipids and glycoproteins  Extra-cellular matrix

5. Phospholipids The primary component of the plasma membrane is phospholipids  Have two non-polar tails (fatty acids) Hydrophobic – water-fearing Hydrophobic – water-fearing  Have polar phosphate head Hydrophilic – water-loving Hydrophilic – water-loving

7. Lipid bilayer Like associates with like  Polar head are attracted to polar water environment  Non-polar tails avoid water and stay together  Called phospholipid bilayer

8. Membrane Proteins Proteins associated with the phospholipid bilayer.  Integral – moves through the bilayer Marker, Receptor, Transport Marker, Receptor, Transport  Peripheral – on one side of the bilayer Enzymes Enzymes

9. Other parts  Cholesterol Prevent freezing Prevent freezing keep membrane firm keep membrane firm  Glycolipids / Glycoproteins Signaling and cell identity Signaling and cell identity polysaccharide attached to lipid / protein polysaccharide attached to lipid / protein  Extra-cellular matrix External proteins that provide additional support External proteins that provide additional support hold shape hold shape

10. Fluid Mosaic Model Plasma membrane is dynamic  Behaves more like a liquid than a solid  Pattern of proteins is always changing  Components move laterally Cannot flip between sides Cannot flip between sides