2. Biology 1 Lipids: Fats

3. Biology 1 Lipids Concentrated energy molecules

4. Biology 1 Lipids  Composed of Carbon, Hydrogen, and Oxygen.  Have a higher ratio of carbon and hydrogen to oxygen compared to carbohydrates.  This means they store more energy per gram

5. Biology 1 2003- 2004 Lipids  Function:  energy storage  very concentrated  twice the energy as carbohydrates!  cell membrane  cushions organs  insulates body  think whale blubber!

6. Biology 1 Lipids  Lipids are NONPOLAR  They do not mix with water  Ex: oil and water

7. Biology 1 Fatty Acids  Unbranched carbon chains that make up most lipids  Long carbon chain with a carboxyl group (-COOH) attached at one end

8. Biology 1 Lipids  Three classes of lipids that contain fatty acids:  Triglycerides  Phospholipids  Waxes

9. Biology 1 Triglyceride  3 fatty acids attached to a molecule of glycerol

10. Biology 1 Phospholipids  Have 2 fatty acids attached to a molecule of glycerol.  Cell membranes are made from phospholipids  heads are on the outside touching water  “hydrophillic”  tails are on inside away from water  “hydrophobic”  forms a barrier between the cell & the outside

11. Biology 1 Phospholipid Bilayer

12. Biology 1 Waxes  Type of structural lipids consisting of a long fatty acid chain joined with a long alcohol chain.  Waterproof  Form protective cover on outside of plants  Used as protective layer in animals  Earwax-helps microorganisms for entering ear canal.

13. Biology 1 Steroids  No fatty acids  Four fused carbon rings with various functional groups  Testosterone and estrogen  Cholesterol- needed for nerve cells and other functions  Too much cholesterol may lead to blockage and heart disease.

14. Biology 1 Saturated Fat vs. Unsaturated Fat

15. Biology 1 Saturated fats  Most animal fats  solid at room temperature  Limit the amount in your diet  contributes to heart disease  deposits in arteries

16. Biology 1 Saturated Fat Always has carbon atoms that are each bonded to 4 other atoms.

17. Biology 1 Unsaturated fats  Plant, vegetable & fish fats  liquid at room temperature  the fat molecules don’t stack tightly together  Better choice in your diet

18. Biology 1 2003- 2004 Saturated vs. unsaturated saturatedunsaturated

19. Biology 1 18 Summary of Fats SaturatedUnsaturated Single bond (straight)Double bond (kinked) SolidLiquid Animal (cholesterol)Plants (cholesterol free) FlakyTenderization “Unhealthy”Essential Fatty Acids and ώ-3s Chemically stableD.B.s reactive, free radicals Cooling as Solid  liquid