1. Cell Membrane

2. Function 1. Separates cytoplasm from external environment 2. Regulates what enters and leaves cell 3. Cell identification 4. Cell-cell communication

3. Plasma membrane regulates movement of materials due to its chemical composition: Phospholipids Cholesterol Proteins

4. Phospholipids  Phospholipids Bilayer Phospholipids have: 1. Hydrophilic head 2.Nonpolar hydrophobic tail

5. Hydrophilic "heads" faces the watery environment inside and outside cell Hydrophobic tail forced to face inward – away from water.

6. Cell Membrane

7. Function 1. Separates cytoplasm from external environment 2. Regulates what enters and leaves cell 3. Cell identification 4. Cell-cell communication

8. Plasma membrane regulates movement of materials due to its chemical composition: Phospholipids Cholesterol Proteins

9. Phospholipids  Phospholipids Bilayer Phospholipids have: 1. Hydrophilic head 2.Nonpolar hydrophobic tail

10. Hydrophilic "heads" faces the watery environment inside and outside cell Hydrophobic tail forced to face inward – away from water.

11. The phospholipids are not bound together – gives the membrane a fluid nature

12. CHOLESTEROL  Function: 1. Stabilizes membrane (structural support) 2. Cell communication (cell-cell and cell-hormone)

13. Some interesting facts  Most common molecule in membrane (>50%)  Due small size and weight – only 20% of membrane mass  Is an amphipathic molecule Homework – find out what this means

14. Proteins  Are embedded in membrane  Serve different functions

15. Functions  1. Channel Proteins - small openings for molecules to diffuse through  2. Carrier Proteins- binding site on protein "grabs” molecules, pulls them into cell  3. Receptor Proteins – act as triggers that set off cell responses (such as release of hormones or opening of channel proteins)  4. Cell Recognition Proteins - ID tags, identify cell to immune system  5. Enzymatic Proteins - carry out metabolic reactions

16. LABEL YOUR DIAGRAM WITH THE FOLLOWING DETAILS

17. Task: Due Wed. Feb 15.  Read pages 47 -49 in your text  Answer questions 1 – 5 in practice section  Explain the structure and function of glycoproteins.  How are liposomes used in cancer treatment and gene therapy?  What role might receptor proteins have in medical disorders such as Hypertension?