LIPIDS

1. LIPIDS

2. What are lipids? FAT CELL • main component in every living cell. • Organic • have carbon chains with attached hydrogen atoms and a carboxyl group at one end.

3. Made up of C, H, O, just like carbs • So what’s the difference? STRUCTURE!

4. Use of lipids in the body • 1. Energy- 2 x energy of Carbs • 2. Fat storage – energy for later use • 3. Shock absorbers for the vital organs

5. 4. Satiety value – makes us feel full longer 5. converted to other compounds- hormones, bile, Vitamin D 6. Insulates – a fat blanket under the skin

6. Three categories of Lipids • Triglycerides – fats & oils • Phospholipids – emulsifiers, component of cell membrane • Sterols – bile, hormones, cholesterol

7. Triglycerides

8. Animal sources Butter Lard Eating different types of triglycerides can have different effects on the body. Plant sources Margarine Oils shortening Forms of Triglycerides

9. Fat per day • 30 % of your calorie intake or less 9 calorie per gram

10. Women 19-49yrs 65 gms 16 tsp • Men 19-49 90 gms 22 tsp • 50+ 60 gms 15 • 1 tsp = 4 gms fat

11. Fats and oils are made from glycerol and fatty acids. • Each glycerol is attached to 3 fatty acids. • They contain carbon , hydrogen and oxygen

12. Carboxyl group -COOH

13. Each fatty acid consists of a hydrocarbon chain with a carboxyl group at one end. • The glycerol molecule has three hydroxyl groups (OH), each able to interact with the carboxyl group of a fatty acid.

15. Essential Fatty Acids • Those the body must get through food. • Can not make these in our bodies.

16. Saturated fats • Animal sources • Fatty acids are saturated-hold all the hydrogen atoms they can. • Solid at room temperature • We make our own.

18. Sources • Animal products

19. Most of the fatty acids are unsaturated have one or more double bonds between their carbon atoms. 2 carbon atoms missing a hydrogen bond join together unsaturated because they could hold more hydrogen atoms than they do. Unsaturated fats

20. Monounsaturated - lacks 2 hydrogen- has one double bond Polyunsaturated- lacks more than 2 hydrogen- 2 or more double bonds

21. Monounsaturated fat

22. Polyunsaturated fat

23. This prevents the fatty acids from packing close together and as a result, unsaturated fats have a lower melting point than do saturated fats. (they are healthier for you!)

24. Trans fatty acids Unsaturated fatty acids - one of two shapes — "cis" and "trans." refers to physical positioning of hydrogen atoms around carbon chain. cis form is more common found in small amounts in various animal products such as beef, pork, lamb and the butterfat in butter and milk.

25. Omega fatty acids • unsaturated fatty acids • first double bond counting from the opposite end from the carboxyl group. • terminal carbon atom (shown here in blue) is called the omega carbon atom. • monounsaturated fatty acid with its single double bond after carbon #3 (counting from and including the omega carbon) is called an omega-3 fatty acid. • But so is a polyunsaturated fatty acid, such as linolenic acid (shown here), if its first double bond is in that position.

26. Some studies have suggested that omega-3 fatty acids help protect against cardiovascular disease.This is known as Good Fat

27. Omega-6 Fatty acids • Omega-6 fatty acids belong to a group of "good" fats called polyunsaturated fatty acids. • Help with immune system • Relax Good dietary sources of omega-3 fatty acids

28. Hydrogenated Vegetable oil • In hydrogenation, plant oils are exposed to hydrogen at a high temperature and in the presence of a catalyst, and turned from liquid into solid!

29. Occur when hydrogenation is done the unsaturated fats become saturated • Hardened margarines

30. Good- Makes them resistant to oxidation- become rancid more slowly • Good- makes them more stable • Bad- makes them more saturated

31. Functions of Triglycerides in Food • Flavor – make foods taste better • Tenderize • Emulsifiers • Aeration – traps air in bubbles

32. Rancidity • Oxidation of fat • Fatty acids combine with oxygen and lose hydrogen • Unsaturated fats with more double bonds are more prone to oxidation • heat, light and oxygen speeds up oxidation

33. Rancid is the term that describes the unpleasant flavors that develop as fats oxidize • Different chemical changes occur for different types of fats • Rancid nuts, meats and potato chips all taste different

34. Phospholipids • Can dissolve in both fat and water • Used as emulsifiers • Found in eggs and peanuts • Main component of cell membranes

36. Sterols A fatty alcohol made from glucose or saturated fatty acids

37. strengthens cell membrane • precursor of other steroids, including sex hormones. • Vital for producing Vitamin D • Used to make bile

38. Your liver produces all the cholesterol you need. • Cholesterol in foods is useless • It can make plaque which builds up on the walls of blood vessels

41. LDL = low density lipoprotein(bad) • Carries cholesterol to to the body tissues to deposit there • When elevated forecast heart and artery disease • Oxidation of LDL causes damage to arteries

42. Antioxidants • Slows oxidation of LDL • Vitamin C, Vitamin E, selenium are antioxidants

43. HDL = high density lipoprotein(good) • HDL cholesterol- carries cholesterol away from tissue

45. Olestra- artificial fat • Remains undigested • Passes through the digestive tract intact • Causes diahrea and digestive upset • Does not allow vitamins to be absorbed by the body