2. Biological membrane

3. What is membrane fluidity? Individual lipid molecules move Chains, headgroups move Lipids themselves diffuse laterally

4. Phospholipid structures Phosphatidylethanolamine PE

5. Cholesterol why is it a major constituent of eukaryotic plasma membranes? polar Rigid steroid ring structure Hydrocarbon tail

6. Cholesterol why is it a major constituent of eukaryotic plasma membranes? polar Rigid steroid ring structure Hydrocarbon tail Prevents chain “freezing” Ends of chains still relatively free to move Restricts movement of lipid chain

8. G protein coupled receptors

9. What do G protein receptors do? - binds to the receptor - receptor changes shape & binds the G protein Extracellular signal molecule = stimulus The G protein  subunit binds GTP & the G protein splits into 2 activated components

10. G protein coupled receptors Receptor Stimulus Effector Response  adrenergic Adrenalin Adenylate cyclase Heart rate acceleration Serotonin Serotonin Adenylate cyclase Many eg neuronal excitability Glucagon Glucagon Adenylate cyclase Glycogen breakdown Rhodopsin Light cGMP phophodiesterase Visual excitation Muscarinic types Acetylcholine Adenylate cyclase Phospholipase C K + channel Excitation/inhibition of neurons Slowing of heart rate Generate cyclic AMP

12. Membrane transport

13. How do molecules or ions cross membranes? via membrane proteins

16. Primary & secondary active transport primary secondary

17. Na + /K + ATPase or pump

21. Na + - linked & passive glucose transport GLUT2

23. GLUT4 and insulin

27. Summary passive Uniport Glucose GLUT 2 active Secondary symport Glucose & Na + Na + -linked glucose transporter active Primary Cl - ABC transporter CFTR active Primary antiport Na + & K + ATPase Na + /K + ATPase Type of transport Species transported Type of protein Membrane protein transporter