Chapter 5Objectives for Chapter 5What Are Fats and Why Do You Need Them?Slide 4Structure of a Fatty AcidFatty Acids Are Found in Triglycerides and PhospholipidsPowerPoint PresentationFatty Acids Vary in Length and StructureSaturated and Unsaturated Fatty Acids Help Shape FoodsTriglycerides Contain Three Fatty Acid ChainsStructure of a TriglyceridePhospholipids Contain PhosphateStructure of a PhospholipidPhospholipids’ Role in Your Cell MembranesSlide 15Sterols Have a Unique Ring StructureStructure of a SterolSlide 18Animation: Lipid AbsorptionWhat Happens to the Fat You Eat?Slide 21Animation: Fat DigestionSlide 23Slide 24LipoproteinsRoles of LipoproteinsHow Does Your Body Use Fat and Cholesterol?Slide 28Slide 29Essential Fatty AcidsHow Much Fat Do You Need Each Day?How Much Fat Do You Need Each Day?Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38What Are the Best Food Sources of Fats?Animation: Fats in FoodFood Sources of the Essential Fatty AcidsWhere’s the Saturated Fat in Your Foods?Composition of Various FatsWhat Are Fat Substitutes and How Can They Be Part of a Healthy Diet?Slide 45Slide 46What Is Heart Disease and What Increases Your Risk?Slide 48Slide 49Slide 50Nutrition in the Real World: The Traditional Mediterranean DietSlide 52Animation: LipoproteinsOn Call: Tips to Raise Good CholesterolSlide 55What Can You Do to Maintain Healthy Blood Cholesterol Levels?Slide 57Slide 58Slide 59Nutrition in the Real World: Mercury and Fish© 2012 Pearson Education, Inc.Chapter 5Fats, Oils, and Other Lipids© 2012 Pearson Education, Inc.Nutrition and You, 2eObjectives for Chapter 5Describe the three classifications of lipids.Explain the differences in the structure of triglycerides, phospholipids, and cholesterol.Describe how fat is digested and absorbed in the body.Explain how fat is transported in the blood.Describe the functions of fat in the body.Define the dietary recommendations for total fat, the essential fatty acids, cholesterol, and trans fat.Identify the major food sources of the different types of fats, including the essential fatty acids, saturated fats, and trans fats.Compare the different fat substitutes currently used in food products.Describe the development of atherosclerosis, including its role in the risk of heart disease.Explain how lifestyle factors can affect the risk for heart disease.© 2012 Pearson Education, Inc.Nutrition and You, 2eWhat Are Fats and Why Do You Need Them?Lipids: category of compounds containing carbon, hydrogen, and oxygen that are hydrophobic (insoluble in water)Fat is the common name for just one type of lipid, known as a triglycerideFats serve multiple functions in foods:Give flaky texture to baked goodsMake meats tenderProvide flavor and aromasContribute to satiety© 2012 Pearson Education, Inc.Nutrition and You, 2eWhat Are Fats and Why Do You Need Them?Fats and other lipids perform important functions in the body:Energy storageInsulationTransport of proteins in bloodCell membrane structureThree types of lipids found in foods and in your body:Triglycerides (fats), phospholipids, and sterolsBasic unit of triglycerides and phospholipids = fatty acids© 2012 Pearson Education, Inc.Nutrition and You, 2eStructure of a Fatty AcidFigure 5.1© 2012 Pearson Education, Inc.Nutrition and You, 2eFatty Acids Are Found in Triglycerides and PhospholipidsFatty acids: chain of carbon and hydrogen atoms with acid group (COOH at one end)Over 20 different fatty acidsCan vary by: 1. length of chain 2. whether carbons have double or single bonds between them 3. total number of double bonds© 2012 Pearson Education, Inc.Nutrition and You, 2eFigure 5.2Saturated and Unsaturated Fatty Acids© 2012 Pearson Education, Inc.Nutrition and You, 2eFatty Acids Vary in Length and StructureSaturated fatty acids: all carbons bonded to hydrogenExample: stearic acid, 18 carbons, solid at room temperatureUnsaturated fatty acids: one or more double bond between carbons (less saturated with hydrogen)More liquid at room temperatureMonounsaturated fatty acids: one double bondExample: Oleic acid, 18 carbons (olive oil)Polyunsaturated fatty acids: more than one double bondExample: essential fatty acids linoleic and alpha-linolenic acids (soybean oil)© 2012 Pearson Education, Inc.Nutrition and You, 2eSaturated and Unsaturated Fatty Acids Help Shape FoodsFigure 5.3© 2012 Pearson Education, Inc.Nutrition and You, 2eTriglycerides Contain Three Fatty Acid ChainsTriglyceride: three fatty acids connected to glycerol “backbone”Most common lipid found in foods and bodyReferred to as fatsSaturated fats have mostly saturated fatty acidsUnsaturated fats have mostly unsaturated fatty acids© 2012 Pearson Education, Inc.Nutrition and You, 2eStructure of a TriglycerideFigure 5.4© 2012 Pearson Education, Inc.Nutrition and You, 2ePhospholipids Contain PhosphatePhospholipids: have glycerol backbone but two fatty acids and a phosphorus groupPhosphorus containing head is hydrophilicFatty acid tail is hydrophobicCell membranes made of phospholipid bilayerMajor phospholipid in cell membrane = lecithin Lecithin used as emulsifier in foods such as salad dressings to keep oils and water mixed together© 2012 Pearson Education, Inc.Nutrition and You, 2eStructure of a PhospholipidFigure 5.5© 2012 Pearson Education, Inc.Nutrition and You, 2ePhospholipids’ Role in Your Cell MembranesFigure 5.6© 2012 Pearson Education, Inc.Nutrition and You, 2eFigure 5.7Keeping a Salad Dressing Blended© 2012 Pearson Education, Inc.Nutrition and You, 2eSterols Have a Unique Ring Structure Sterols are comprised mainly of four connecting rings of carbon and hydrogenExample: cholesterol Important role in cell membrane structurePrecursor of important compounds in bodyNot required in diet since body makes all cholesterol needed© 2012 Pearson Education, Inc.Nutrition and You, 2eStructure of a Sterol Figure 5.8© 2012 Pearson Education, Inc.Nutrition and You, 2eFigure 5.9Three Types of Lipids© 2012 Pearson Education, Inc.Nutrition and You, 2eAnimation: Lipid Absorption© 2012 Pearson Education, Inc.Nutrition and You, 2eWhat Happens to the Fat You Eat? Mouth: chewing, lingual lipaseStomach: gastric lipase: diglyceride and one fatty acidSmall intestine:Bile acids: emulsify fatPancreatic lipase: two fatty acids and glycerolLecithin in bile packaged with monoglycerides and