1. CELL MEMBRANE: FLUID MOSAIC

2. CELL/ PLASMA MEMBRANE Separates the inside of the cell from its environment Receives messages from outside Allows things to move in and out of the cell Has markers that identify the type of cell

3. WHAT ARE CHARACTERISTICS OF THE CELL MEMBRANE? Selectively permeable Only some things can pass through the membrane Polar, charged and large molecules can only get through membrane via transport proteins Composed of phospholipids Proteins

4. BI-LAYER OF PHOSPHOLIPIDS Heads are polar hydrophilic Tails are nonpolar hydrophobic Steroid molecules make membrane rigid. think: What do: “hydro”, “bi”, “philic” & “phobic” mean?

5. MACROMOLECULES: LIPIDS Lipids are fats & oils. Lipids are fats & oils. Lipids are composed of only C,H,O. Lipids are nonpolar. Lipids are composed of glycerol and 3 fatty acids. Lipids can be saturated (solid at room temperature) or unsaturated (liquid at room temperature) The glycerol forms the “head” and The 3 fatty acid chains the “tails”

6. PROTEINS EMBEDDED IN BI- LAYER Peripheral proteins act as recognition sites on the outside of the cell Inside the cell they are enzymes Integral proteins act as channels that move things through the membrane Think: What do: “peripheral” & “integral” mean? How does this relate to where the proteins are in the plasma membrane?

7. FLUID MOSAIC MODEL Phospholipids & proteins move about. (fluid) Membrane has many types of molecules in it (mosaic)

8. SUMMARIZE THE MOST IMPORTANT INFORMATION ABOUT THE CELL MEMBRANE IN A PARAGRAPH