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SWBAT: 1.Describe a lipid 2.Describe the classes of lipids SWBAT: 1.Describe a lipid 2.Describe the classes of lipids Chapter 15 Lipids Slide 2 What are lipids? Group of molecules not defined by structure but by common characteristics They are: non-polar soluble in non-polar solvents like methylene chloride, gasoline, ether not soluble in polar solvent like water fats, oils, fatty acids, waxes, steroids, cholesterol, fat soluble vitamins Slide 3 Lipids and Health BMI: Body Mass Index: Body Fat vs Obesity Blood Lipids Slide 4 CAD: Coronary Artery Disease Lipid deposits clogging arteries in the body and heart Risk Factors for CAD Hypertension, Diabetes, elevated cholesterol smoking sedentary lifestyle stress obesity male sex family history older age Slide 5 Types of Lipids Saponifiable Lipids: Prostaglandins Waxes Tricylglycerols Glycerophospholipids Non-Saponifiable Lipids: Cholesterol Steroid hormones Can be Hydrolyzed Can NOT be Hydrolyzed Slide 6 Homework Chapter 15.1 Pg 497 #15.2 15.4 (even) Slide 7 SWBAT: 1.Write structures of fatty acids 2.ID saturated and unsaturated fatty acids Chapter 15 Fatty Acids Slide 8 Fatty Acids Contains a long carbon chain attached to a carboxylic acid on C1 Typically contain and even number of carbon atoms between 10 and 20 Dodecanoic Acid Lauric Acid Slide 9 Fatty Acids They are: Aliphatic molecules they are both hydrophobic and hydrophilic Butoverall they are hydrophobic HydrophilicHydrophobic Cell Membrane Slide 10 Fatty Acids to know Laura, My Palm Stinks! Lauric Acid (C12) Myristic Acid (C14) Palmitic Acid (C16) Stearic Acid (C18) Slide 11 Types of Fatty Acids Saturated Fatty Acids: Only single bonds between the carbon atoms Monounsaturated Fatty Acids: Have one double bond in the carbon chain Polyunsaturated Fatty Acids: Have two or more double bonds Slide 12 Unsaturated Fatty Acids trans double bonds cis double bonds Slide 13 Shapes of Unsaturated Fatty Acids Slide 14 Fatty Acids: Physical Properties Saturated and trans Fatty Acids: High melting points (solids) Perfect alignment high Van de Waals intermolecular attractions Trans fatty acids do not naturally exist they are a man made product and are the most stable fatty acids Slide 15 Fatty Acids: Physical Properties Unsaturated cis Fatty Acids: Lower melting point (liquid at room temp) Do not have perfect alignment due to kinks in chain low Van de Waals Less stable double bonds can break Slide 16 Both are: C 18 H 36 O 2 Saturated MP of 69 Unsaturated MP of 13 Slide 17 Prostaglandins They are: Small polyunsaturated Fatty Acids that act like hormones mediating a range of symptoms from inflammation to blood pressure Synthesized from Arachidonic Acid (AA) Slide 18 Prostaglandins Most have a hydroxyl group on C11 and C15 and a trans double bond at C13 PGE - those with a ketone on C9 PGF - those with a hydroxyl group on C9 Slide 19 Inflammation is a Natural response to infection and injury Disease like rheumatoid arthritis (inflammation of the joints) Slide 20 Why do we care? Slide 21 Non Steroidal Anti- Inflammatory Drugs (NSAIDs) Drug class that includes: Aspirin Ibuprofen Naproxen (Alveve) Ketoprofen (actron) Nabumetone (Relafen) Long term use can result in liver, kidney and gastrointestinal damage Slide 22 NSAID effect and side effect Stomach side effect Video Links Slide 23 Homework Chapter 15.2 Pg 503 #15.6 15.18 (even) Slide 24 SWBAT: 1.Write structural formula of wax, fat or oil 2.ID the reaction of a fatty acid and an alcohol or glycerol Chapter 15 Waxes, Fats and Oils Slide 25 Waxes Found in many plants and animals (leaves, stems, skin, fur and feathers) Is an ester of a saturated Fatty Acid and a long-chain alcohol (14-30 carbon atoms) Slide 26 Fats and Oils: Triacylglycerols The body stores Fatty Acids as fats and oils Also called tryglycerides Produced by esterification of glycerol and Fatty Acid groups Slide 27 Fats and Oils: Triacylglycerols Most fats and oils are mixed triacylglycerolds with two or three different Fatty Acids from stearic acid from palmitic acid from myristic acid can be saturated or unsaturated Slide 28 Writing Structures for Triacylglycerol Each Fatty Acid is attached by an ester bond to one of the hydroxyl groups in glycerol Alcohol Part: In triglycerides always glycerol Carboxylic Acid Part: Three Fatty Acids Slide 29 Fats and Oils: Physical Properties A fat is a solid at room temperature (fats in meat, butter, cheese) There are exceptions Typically from an animal source Oil is usually liquid at room temperature (oils olive, peanut, sunflower) Typically from a plant source Slide 30 Fats and Oils: Physical Properties Saturated Fatty Acids have higher melting points because they pack together tightly Animal fats usually contain more saturated Fatty Acids than vegetable oils Slide 31 Melting Points Slide 32 Homework Chapter 15.3 Pg 507-508 #15.20 15.28 (even) Slide 33 SWBAT: Draw the structure of the product from a reaction of triacylglycerol with hydrogen, or an acid or base Chapter 15 Chem Props of Triacylglycerols Slide 34 Hydrogenation Hydrogenation of unsaturated fats converts carbon-carbon double bonds to single bonds Hydrogen gas is heated through oil with a nickel catalyst Partial hydrogenation changes oil to a soft, semisolid fat (crisco) H2H2 Slide 35 Why? Chemical process patented in the 1940s used to convert oil surpluses from soybean farming into spreadable fats (margarines) to alleviate butter shortage Slide 36 Problem Incomplete hydrogenation leads to the formation of trans- double bonds Trans Fats Trans Fats raise LDL (bad cholesterol ) levels in the body Consumption of Trans Fats is correlated with a rise in CAD during 1960-2000 FDA prohibits use of Trans Fats & requires labeling trans fats in our food Video Link Slide 37 Hydrolysis Breaking the ester bond yielding fatty acid & glycerol First step in the digesting of triglycerides in the body Carried out by the enzyme lipase Glycerol is soluble in water Fatty Acids are not H+H+ lipase Slide 38 Saponification (sapon = soap) Reacting triglycerides with a strong base Yields glycerol and Fatty Acid Salts (soap) Glycerol tritearate + 3 NaOH glycerol + 3 sodium stearate Slide 39 What is Soap Soaps are aliphaic molecules that have a polar part (facing water molecules) and a non- polar part (facing greasy dirt) Ancient soap making Animal fats are heated with a strong base (lye from burnt limestone) Fatty acid salts Sodium paltmitate: Na + - OOC-(CH 2 ) 14 -CH 3 Soap Making Video Slide 40 Food Labels Slide 41 Slide 42 Olestra Fatty Acids from cottonseed or soybean oils Composed of 6 to 8 long- chain Fatty Acids attached to sucrose rather than glycerol We cant digest it so Fake Fat goes straight through our system GI problems occurred Slide 43 Homework Chapter 15.4 Pg 512-513 #15.30 15.36 (even) Slide 44 SWBAT: 1.Describe the characteristics of glycerophospholipids Chapter 15 15.5 Glycerophospholipids Slide 45 What are Glycerophospholipids? Similar to triglycerides except one hydroxyl group is replaced by the ester of phosphoric acid and an amino alcohol Bonded through a phosphodiester bond Glycerophospholipids Triglycerides Slide 46 Amino Alcohols Three amino alcohols found in glycerophospholipids are: choline ethanolamine serine Slide 47 Lecithins Lecithins contain choline Fatty Acids can be same, different, saturated, unsaturated or mixture Abundant in: brain tissue nerve tissue egg yolks wheat germ yeast Slide 48 Cephalins Cephalins contain ethanolamine and sometimes serine Abundant in: brain tissue nerve tissue egg yolks wheat germ yeast Slide 49 Polar? Contain both polar and nonpolar regions Ionized alcohol and phosphate portion is called the head Can hydrogen bond with water Two Fatty Acids represent the tail Hydrophobic Tails Hydrophilic Head Group Slide 50 Polar and Nonpolar Regions Most abundant in lipids in cell membrane Nonpolar Tails Polar Head Slide 51 Homework Chapter 15.5 Pg 515 #15.38 15.42 Slide 52 SWBAT: Describe the structure of steroids Chapter 15 Cholesterol & Steroid Hoemones Slide 53 General Structure Steroidnucleus: Three cyclohexane rings A,B,C One cyclopentane ring D Slide 54 Types of Steroids Cholesterol Lipoproteins Steroid Hormones Anabolic Steroids Slide 55 Why does it have the ending ol? Cholesterol Most abundant steroid in the body Slide 56 Facts about Cholesterol its part of every cell membrane insulates nerve and brain tissue forms bile for digestion forms Vitamin D in skin starting material for steroid hormones: sex hormones, cortisone leads to heart attacks Slide 57 Lipid Metabolism Cholesterol is so important that the body does not rely on what you eat. It manufactures 80% of the cholesterol needed Serum Cholesterol Levels in your body can be measured via blood tests: Lipid Panels Slide 58 Lipid Panels What health care professional look for Total Cholesterol HDL: High density Cholesterol good LDL: Low density Cholesterol bad Slide 59 Why? Lowering Cholesterol Levels is a business. Food industry: fat free/cholesterol free items lean meats low fat dairy hunt against saturated fats Pharmaceutical industry: statin drugs HMG-CoA reductase inhibitors Slide 60 LIPITOR The most widely used drug in the world Pharmaceutical drug lowering cholesterol levels Reaps 26 billion in sales per year worldwide Side effects range from diabetes, to cancer Slide 61 Cholesterol Levels Cholesterol levels show individual variations due to: Genetics Age General health: cholesterol is an anti- inflammatory, anti-stress substance, it can rise due to reasons ranging from stress, lack of sleep, drugs and chronic diseases (diabetes) Diet: Plant based diets are correlated with lower cholesterol levels Slide 62 Cholesterol in Food Egg250 mg Crab/Shrimp150 mg Beef85 mg White chicken75 mg Fish40 mg All animal based food contain cholesterol All plant based foods contain no cholesterol Slide 63 Cholesterol and CAD Artheriosclerosis is the main cause of CAD It is caused by plaque that clog arteries Plaque are cholesterol deposits Q: What makes cholesterol form plaque? A: Inflammation Slide 64 Transporting Fats in Blood Lipids are insoluble in the blood (=water) Lipids are transported from spherical vesicles called Lipoproteins Skin: Phospholipids, Proteins Inside: Cholesterol, Triglycerides Slide 65 Steroid Hormones Sex Hormones Estrogen: development of female sex characteristics Testosterone: development of male sex characteristics including muscle anabolism Progesterone: prepares uterus for fertilized egg Slide 66 Steroid Hormones Corticosteroids Steroid Hormones produced by the adrenal glands Natural Cortisone Drug Prednisone Helps with: stress response immune response regulation of inflammation Slide 67 Anabolic Steroids Synthetic Testosterone derivatives Promote muscle growth, reduce body fat Short term side effects: broken bones, ruptured tendons, kidney pain Long term use lead to kidney, heart, liver damage Legal steroid Tren Slide 68 Homework Chapter 15.6 Pg 522 #15.44 15.54 (even) Slide 69 SWBAT: 1.Describe the composition and function of the lipid bilayer in cell membranes Chapter 15 15.7 Cell Membranes Slide 70 Cell Membrane Composed of phospholipid bilayer Polar head & nonpolar tails Semipermeable items can enter and leave Slide 71 Lipid Bilayer Double row arrangement of phospholipids Hydrophilic polar heads align on outer edges of membrane Hydrophobic nonpolar tails move to center Slide 72 Fluid Mosaic Model Lipid bilayer contains unsaturated Fatty Acid Cis double bonds causes a non-rigid structure In liquid like bilayer: Proteins Carbohydrates Cholesterol Slide 73 Homework Chapter 15.7 Pg 524 525 #15.56 15.62