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LIPIDS & PROTEINS I. LIPIDS: § Commonly called fats & oils § Contain more C-H bonds and less O atoms than carbohydrates. l Ex: C57H110O6 § Nonpolar; therefore repel water (insoluble) I. LIPIDS: § Functions of lipids in our body: 1. Long term energy storage (used when carbohydrates are NOT available) 2. Insulation 3. Protect body tissue (cushioning) WHICH HAS MORE ENERGY – LIPIDS OR CARBS? § One gram of fat contains TWICE as much energy as one gram of carbohydrates. Therefore, fats are better storage compounds! Types and Examples of Lipids: 1. Sterols- steroids 2. Waxes – bee, furniture, ear, car 3. Cholesterol- in egg yolks, red meat 4. Fats- from animals 5. Oils – from plants Structure of Lipids: § Basic building blocks: 3 fatty acids + 1 glycerol § Fatty Acids l Long chains of carbon with a carboxyl group at one end Structure of Lipids: § One fatty acid: Structure of Lipids: § Glycerol and each fatty acid chain are joined to each other by dehydration synthesis. Structure of a lipid (1 glycerol + 3 fatty acids): 3 types of fats: 1. Saturated fats = fatty acid chains of carbon with only single bonds between the carbon atoms l Solid at room temperature • Ex: butter 3 types of fats: 2. Unsaturated fats = fatty acid chains of carbon with ONE double bond between the carbon atoms l Liquid at room temperature • Ex: Olive oil 3 types of fats: 3. Polyunsaturated fats = more than one double bond between the carbon atoms in the chain Structural formulas for saturated and polyunsaturated fatty acids: Polyunsaturated Fatty Acid What happens to LIPIDS in the body? § Broken down by the digestive system into fatty acids and glycerol which are then absorbed into the body through the bloodstream, where the body cells take the fatty acids and glycerol and make needed lipids I. Lipids: § Triglycerides = Majority of fat in organism consist of this type of fat molecules l Derived from fats eaten in foods or made in the body from other energy sources like carbohydrates. I. Lipids: Calories ingested in a meal and not used immediately by tissues are converted to triglycerides and transported to fat cells to be stored. Storage – 3 month supply of energy vs. glycogen’s 24 hour supply I. Lipids: Hormones regulate the release of triglycerides from fat tissue so they meet the body's needs for energy between meals. Excess Triglycerides- Life Applications: Cause plaque to build up Arteriosclerosis = walls of the arteries get thick and hard; fat builds up inside the walls and slows the blood flow • Cause blood clots – heart attacks, strokes Excess Triglycerides- Life Applications: Hypertension (high blood pressure) II. PROTEINS: Large complex polymer composed of C, H, O, N, & sometimes S Basic building blocks: Amino acids 20 different amino acids II. PROTEINS: Example amino acid: II. PROTEINS: Amino acids are linked together by dehydration synthesis to form a protein II. PROTEINS: Ex: 2 amino acids joined by dehydration synthesis PROTEIN (dipeptide) II. PROTEINS: Peptide bond = a covalent bond that joins amino acids to each other II. PROTEINS: Proteins- named for the number of amino acids that make them Ex: otwo amino acids = dipeptide othree amino acids = tripeptide omany amino acids = polypeptides II. PROTEINS: Essential Amino Acids: 10 of the 20 amino acids are “essential” because they are required by the body but are NOT created by it. oAs a result, it must be provided by our diet. If one is missing then proper growth and repair cannot be maintained. Functions of proteins in our body: 1. Muscle contraction 2. Transport oxygen in the bloodstream Functions of proteins in our body: 3. Provide immunity 4. Carry out (antibodies) chemical reactions What happens to PROTEINS in the body? Broken down by the digestive system into amino acids which are then absorbed into the body through the bloodstream, where the body cells take the amino acids and makes protein for muscles.
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