3. Lipid Structure Fats, Oils, Waxes Provide energy for cells, cell structure, insulation – Lipids & Proteins compose the cell membrane – Cholesterol: gives cell membrane flexibility

4. Lipid Structure Fats, Oils, Waxes Provide energy for cells, cell structure, insulation – Lipids & Proteins compose the cell membrane – Cholesterol: gives cell membrane flexibility Structure (2 parts): – “Head” = glycerol – “Tails” = fatty acids Monomer: Fatty Acid Polymer: Lipid Glycerol molecule Fatty acids

5. How does glycerol… bond with these fatty acids? C CH O OH C C H H H H H H C CH O C C H H H H H H C CH O C C H H H H H H CCC HHH H H Dehydration Synthesis C CH O C C H H H H H H C CH O C C H H H H H H C CH O C C H H H H H H H2OH2O H2OH2OH2OH2O

6. How is this lipid broken down? Hydrolysis CCC HHH H H OOO C CH O C C H H H H H H C CH O C C H H H H H H C CH O C C H H H H H H H2OH2O H2OH2O H2OH2O CCC HHH H H OOOHOH C CH O C C H H H H H H OH CCC HHH H H OHOHOOHOH C CH O C C H H H H H H CCC HHH H H OHOHOHOHOHOH C CH O C C H H H H H H

7. Saturated Fats Long chain of C-C single bonds Each C is “saturated” with H atoms C C CCCCCCH H HHHHHHH H HHHHHHH C HO O Saturated fatty acid

8. Saturated Fats Long chain of C-C single bonds Each C is “saturated” with H atoms Solid at room temps Charles Sporn from NYC, USA

9. Saturated Fats Long chain of C-C single bonds Each C is “saturated” with H atoms Solid at room temps Very common in animal fats Butter is made from cow milk Lard is pig fat

10. Unsaturated Fats Long chain of C bonds (some double bonds) —Causes the chain to be crooked Unsaturated: Less space for H atoms Unsaturated fatty acid C C CCC C C C H H H HHHH H H H HHHHH C HO O

11. Unsaturated Fats Long chain of C bonds (some double bonds) —Causes the chain to be crooked Unsaturated: Less space for H atoms Liquid at room temps

12. Unsaturated Fats Coconut oil Long chain of C bonds (some double bonds) —Causes the chain to be crooked Unsaturated: Less space for H atoms Liquid at room temps Plant oils Olive oil comes from olive trees

13. C C CCC C C C H H H HHHH H H H HHHHH C HO O Saturated vs. Unsaturated 12345678 9 18 1716151413121110 12345 6 7 8 9 1615141312 11 10 The double bond reduces the need for more H atoms to stabilize the molecule. C C CCCCCCH H HHHHHHH H HHHHHHH C HO O

14. Normally, blood flows freely… Artery RBC

15. High Cholesterol Levels Artery RBC Cholesterol build up on the wall of aertieries Reduced circulation… Blood clots… High blood pressure RBC

16. Atherosclerosis High240+ Borderline High200-239 DesirableLess than 200 Total Cholesterol Level

17. review 1)What are the two parts of a lipid called? 2)Which part is the “head”? Which part are the “tails”? 3)How do small fatty acids and glycerol molecules bond to make a lipid? 4)How do saturated and unsaturated fatty acids differ? 5)Which lipid gives cells their flexibility? 6)Why are saturated fats less healthy?