Carbohydrates 1 Dietary carbohydrates and sources o Starch grain products o Fiber legumes vegetables and fruits o Sugars natural sugars milk fruits added sugars 2 Classification of carbohydrates Common mono di and polysaccharides Glucose is the energy source for all cells Monosaccharides glucose fructose galactose Maltose glucose glucose Sucrose glucose fructose Lactose glucose Starch storage form of energy in plants Glycogen storage form of energy in galactose animals stored in liver and muscle Fiber cannot be digested Why o There is no digestive enzyme that can break the chemical bonds of fiber 3 Carbohydrate digestion Begins in the mouth Functions of pancreatic amylase maltase lactase sucrose o Pancreatic Amylase breaks down starch into maltose o Maltase digests maltose into glucose o Lactase digests lactose into glucose and galactose o Sucrase digests sucrose into glucose and fructose Digestion products glucose fructose galactose o Primarily glucose a Cannot digest lactose because lactase production is insufficient either due to age or b All milk products do not need to be removed from diet some can be eaten 4 Causes of lactose intolerance inability to synthesize 5 Glucose in the body Glycogen formation glycogen breakdown gluconeogenesis o Glycogen is formed when we eat stored in muscles and liver o Glycogen is broken down to glucose to provide energy o Gluconeogenesis the formation of new glucose by breaking down other compounds protein fats etc Blood glucose homeostasis the function of insulin and glucagon o Insulin makes the blood glucose enter the cell therefore lowering the level of blood glucose o Glucagon stimulates liver to breakdown glycogen to produce more glucose to increase the blood glucose level secreted when glucose is low Diabetes o Blood glucose level is above normal level due to inadequate insulin production or insulin isn t effective 6 Identify added sugars on the ingredient label a Corn syrup solids dextrose high fructose corn syrup honey sucrose dextrose fructose etc 7 Health effects and Recommended intake AMDR for carbohydrates Example Michael eats 2500 kcalories a day and 300 grams of carbohydrates Is he consuming enough carbohydrates according to the Acceptable Macronutrient Distribution Range for carbohydrates Answer 300 g 4 kcal g 1200 kcal 1200 2500 0 48 48 Yes 45 65 of calorie intake should come from carbohydrates Recommended intake of fiber for men and women 35 grams per day for men 25 grams per day for women Proteins 1 Amino acids Protein is made of amino acids Basic structure of amino acids o Side group varies with different amino acids o Central C Atom o H atom o Carbonyl Acid Group COOH o Amino Group NH2 Essential amino acids the body cannot synthesize must get through diet 9 2 Structure of proteins Amino acids are linked by peptide bonds Four levels of protein structures o Primary amino acid sequence the 20 amino acids can be linked in a variety of sequences o Secondary polypeptide shape sections of polypeptide chain twists into specific shapes i e helix due to weak electron attractions within chain o Tertiary polypeptide tangles long polypeptide chains twist and fold into shapes o Quaternary multiple polypeptide interactions Denaturation o When a protein is subject to heat acid etc where structure is broken and uncoiled it loses its function Ex cooking an egg 3 Protein digestion Digestion products amino acids tripeptides dipeptides 4 Functions of proteins a Structural building blocks of muscles skin and blood enzymes help begin chemical reactions hormones insulin and glucagon for example regulators of fluid balance regulator of acid base balance act as a buffer attract positive H atoms to the negative surface of the protein transporters carry nutrients and molecules in body s fluids antibodies source of energy and glucose only during times of starvation or insufficient carb intake 5 Protein metabolism Excess amino acids from dietary protein intake can NOT be stored in the body they can be converted to body fats 6 High quality protein vs low quality protein a High Quality animal and soy protein can be digested easily and contain all 9 essential amino acids b Low Quality plant proteins contain only some essential amino acids 7 Recommended intake AMDR i 10 35 of cal from protein RDA i 8 gram of protein per kilogram of body weight Example Joe weighs 180 lbs Based on the RDA for protein how many grams of protein should he consume each day Divide body weight in pounds by 2 2 to get body weight in kilograms Answer 180 lbs 2 2 81 8kg 81 8 kg 0 8g kg 65g Lipids 1 Lipids are a group of compounds that are insoluble in water 2 Fatty acids Identify saturated fatty acids monounsaturated and polyunsaturated fatty acids o Saturated Fatty Acids contain only single carbon carbon bonds o Monounsaturated only one carbon carbon double bond MUFA o Polyunsaturated two or more carbon carbon double bonds PUFA Give the omega number of an unsaturated fatty acid based on its chemical structure Essential fatty acids the body cannot synthesize linoleic acid and linolenic acid 3 Triglycerides Composed of three fatty acids attached to one glycerol Fats saturated fats vs Oils unsaturated fats o Fats are solid at room temp and more sat oils are liquid with more unsat Partial hydrogenation of vegetable oils o more stable o produces trans fatty acids Function o Stored in adipocytes and can be used as energy in times of fasting state 4 Phospholipids and sterols Phospholipids are the major constituents of cell membranes Most common sterol cholesterol Sterols cannot provide energy Cholecystokinin CCK signals the gallbladder to release bile into small intestine to 5 Triglycerides digestion emulsify fat Pancreatic lipase o Hydrolyze triglycerides into monoglycerides and fatty acids 6 Lipid transport lipoproteins Vehicles for transporting lipids in blood stream Functions of chylomicrons VLDL LDL and HDL i Chylomicrons deliver dietary lipids mostly triglycerides from small intestine to the rest of the body ii Very Low Density Lipoprotein deliver lipids synthesized in the liver and other tissues iii Low Density Lipoproteins composed primarily of cholesterol delivers cholesterol to tissues depositor of cholesterol iv High Density Lipoprotein pick up cholesterol from tissues and return it to liver for disposal Health implications of LDL and HDL i High level of LDL can deposit a high level of cholesterol into endothelial cells of arteries which could lead to athrosclerosis ii High