Unit 5 Nutrition Key Concepts Identify foods that are rich sources of the 4 main classes of organic macromolecules as well as vitamins and minerals Identify differences between good and bad fat Calculate caloric contributions by carbohydrates proteins and lipids from the nutritional information on a food label Explain how bad health choices can lead to problems like obesity factors that influence obesity and ways to treat obesity Explain the role of body mass index BMI as a measure of health status of an individual Explain the role of oxygen in cellular respiration Understand implications of a block in the energy conversion machinery of the cell 4 11 Obesity Class Notes Mouth 500 Digestive Tract 1000 Functional contributions of gut microbiota Break down complex carbohydrates Synthesize vitamins Regulator of drug bioavailability 55 18 5 24 9 normal 25 29 9 overweight 30 and above obese Measures of body fat BMI waist circumference waist to hip ratio BOD PODS DEXA scans calipers BIA blood levels of lipids Problems associated with obesity hypertension type II diabetes hyperlipidemia cardiovascular disease depression Treatment of obesity weight loss pills surgery gastric banding gastric bypass weight loss programs Types of Carbohydrates Monosaccharide glucose fructose galactose Disaccharide lactose sucrose maltose Polysaccharide glycogen starch cellulose Organic Macromolecules carbohydrates lipids proteins and nucleic acids 1 organic molecules must contain carbon Amino acids Some like water some don t Our bodies produce some but won t produce others Building blocks of proteins Come in different shapes and sizes Fatty Acids Building blocks for fats Saturated have no double bonds in its chain Solid at room temperature Unsaturated have one or more double bonds in its chain Liquid at room temperature because the bends in the chain prevent them from being closely packed together Triglyceride the fatty acid chain may be saturated or unsaturated Main storage form of lipid Carbohydrates attached to proteins on the cell surface connect two cells through the extracellular matrix Proteins form channels for the passage of molecules signals from the outside of the cell to the inside Phospholipids reside in the membrane and serve as a barrier to external environment Cholesterol makes the cell membrane fluid and flexible Nutrition Facts Label Select foods low in sodium A food is low in fat if the calories from fat multiplied by 3 are less than the calories per serving fat calories should not make up more than a third of total calories Look for high fiber A food high in protein has 7 grams or more per serving Consume less than 300mg of cholesterol per day Reading Notes 5 6 The Chemical Building Blocks of Life There are 4 major classes of molecules carbohydrates nucleic acids proteins and lipids Organic molecules are biomolecules that include at least 1 carbon hydrogen bond Ex Sugars and amino acids 2 Macromolecules larger assemblies of atoms created by small organic molecules linked up Ex starch and proteins Monomers small repeating units of macromolecule Polymers what macromolecules are called when contain monomers A polymer may be a natural or synthetic macromolecule comprised of repeating units of a smaller molecule monomers Functional group clusters of covalently bonded atoms that have the same distinctive chemical properties no matter what molecule they are in 5 7 Carbohydrates Carbohydrates are sugars and their polymers In a carbohydrate for each Carbon there are 2 Hydrogen and one oxygen Monosaccharides simplest sugar molecules Often referred to by the of carbons between 3 and 7 Ex Glucose C6H12O6 Disaccharide two covalently joined monosaccharides Ex table sugar sucrose Polysaccharide large polymers built by many linked monosaccharide Ex cellulose 5 8 Proteins Major functions of protein storage structure bone cartilage hair transport hemoglobin catalysts enzymes Built from amino acids Polypeptide linear chains of amino acids covalently linked their sequence of amino acids primary structure how it folds secondary structure last fold tertiary structure Denaturation destruction of a protein s 3 D structure 5 9 Lipids Lipids hydrophobic molecules made by living cells most from fatty acids Fatty acid in which all the Carbon atoms in the hydrogen chain are linked by single covalent bonds are saturated 3 fatty acids typically solids because can pack tightly together if there are any double bonds it is an unsaturated fatty acid typically liquids at room temperature Animals store surplus energy as triglycerides 3 fatty acids bonded to a glycerol Phospholipids help make up cell plasma membrane A phospholipid is a molecule of 2 fatty acids joined to a glycerol with a phosphate group very polar 27 1 Nutrients that Animals Need All animals need 3 main categories of large organic molecules from food carbohydrates lipids and proteins Dietary fiber indigestible plant polysaccharides that slow down the speed at which carbs are digested Absorbed monosaccharides fatty acids and amino acids enter bloodstream and go into cells become building blocks for carbs lipids and proteins Monosaccharides fatty acids and monoglycerides also release energy when broken down through glycolysis or cellular respiration 8 amino acids must come from food essential amino acids Vitamins small organic nutrients needed by our bodies in tiny amounts Have multiple functions assist enzymes delivery signaling antioxidants 2 classes water soluble and fat soluble Minerals inorganic chemicals that have critical biological functions 4 18 Digestion Class Notes Digestion Mouth the saliva teeth break it down esophagus stomach where chemicals help break it down small intestine large intestine rectum anus toilet 4 Only certain simple sugars can pass from the outside of the plasma membrane to the inside A few di and tripeptides can cross plasma membranes Triglycerides fats are the main form in which energy is stored in the animal body Triglycerides are too large to be absorbed directly Enzymes involved in the breakdown of food Amylase starch Pepsin Proteins Chymotrypsin Proteins Trypsin proteins Lipase Lipids Pepsin is produced as pepsinogen activated by being cut to reveal active site Active at 1 5 2 0pH Inactive at 7 0pH Sugar Substitutes Aspartame Equal Sucralose Splenda Saccharin Sweet N Low Mannitol Sorbitol Sugar alcohols Stevia steviol glycosides derived from a plant source 300x sweeter than sugar thought to help reduce hypertension and