1. THE FRONTIERS OF LIFE lectures in physiology and development in the light of evolution David Barrington, 2008

2. The main point to be made here is that certain kinds of molecules have physical and chemical properties that allow them to self-assemble into orderly structures, and these are the molecules used by living cells. Deamer, 1999

3. The Membrane Frontier 1.Membrane Structure - phospholipids 2.Membrane Proteins and Functions 3.Origin of Membranes; Origin of Life

4. Soap function relates to membrane structure.

5. Soap bubbles are inside-out lipid bilayers (protecting water from evaporation, so it persists as a liquid in the air longer).

6. Phospholipid s are amphiphilic: a single molecule has a polar and non-polar region.

7. Building a phospholipid

8. Phospholipids are the key and common molecules in the membrane.

9. LE 7-2 Hydrophilic head Hydrophobic tail WATER phosphatidyl choline.

10. LE 7-5a Lateral movement (~10 7 times per second) Flip-flop (~ once per month) Movement of phospholipids

11. The Membrane Frontier 1.Membrane Structure - phospholipids 2.Membrane Proteins and Functions 3.Origin of Membranes; Origin of Life

12. LE 7-3 Hydrophilic region of protein Hydrophobic region of protein Phospholipid bilayer

13. LE 7-6 Membrane proteins Mixed proteins after 1 hour Hybrid cell Human cell Mouse cell

15. LE 7-7 Fibers of extracellular matrix (ECM) Glycoprotein Carbohydrate Microfilaments of cytoskeleton Cholesterol Integral protein Peripheral proteins CYTOPLASMIC SIDE OF MEMBRANE EXTRACELLULAR SIDE OF MEMBRANE Glycolipid

16. LE 7-9a Enzymes Signal Receptor ATP Transport Enzymatic activity Signal transduction

17. LE 7-9b Glyco- protein Cell-cell recognition Intercellular joining Attachment to the cytoskeleton and extra- cellular matrix (ECM)

18. Figure 36.2 A chemiosmotic model of solute transport in plant cells

19. The Membrane Frontier 1.Membrane Structure - phospholipids 2.Membrane Proteins and Functions 3.Origin of Membranes; Origin of Life

20. Lipids self- assemble into spheres in water.

21. Fatty-acid length matters.

22. Meteorite contents witness ancient non- biological organic molecules

23. including molecules that form osmotically functional vesicles Nonanoic acid Polycyclic aromatic hydrocarbons

24. The Membrane Frontier 1.Membrane Structure - phospholipids 2.Membrane Proteins and Functions 3.Origin of Membranes; Origin of Life