NHM 101 1nd Edition Exam 4 Study Guide Outline of Last Lecture I Lifestyle Nutrition Outline of Current Lecture II Study Guide for final exam Current Lecture Six Classes of Nutrients Carbohydrates Proteins Lipids Vitamins Minerals Water Which nutrients provide energy Carbohydrates Lipids Proteins Any nutrition calculations that we have covered in class Go back over the nutrition calculations assignment for practice Dietary Reference Intakes including UL RDA and AI UL highest level of daily nutrient intake that is unlikely to have adverse health effects RDA amount of nutrients needed to meet requirements of almost all healthy individuals AI nutrient recommendation based on observed or experimentally determined appromimation Best Source of Nutrition Information Qualified nutrition professionals Some physicians Registered dietitians These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Dietary Guidelines Reviewed every five years USDA and HHS jointly create each edition MyPlate Current food icon We are consuming too many foods high in fat and added sugars Too few veggies fruits whole grains and milk products Food Groups Fruits Vegetables Grains Protein foods Milk and milk products Nutrition Facts Labels and Nutrition Claims on Labels Fat free less than 5 gm of fat per serving Low fat less than 3gm of fat per serving Trans fat free less than 5 gm of trans fat and less than 5g of saturated fat per serving Light or lite 1 3 fewer calories than the comparison food Organic at least 95 of products ingredients have been grown and processed according to USDA regulations Anatomy of Digestive Tract Mouth Esophagus Stomach Small intestine Large intestine Rectum Anus Movement of Food through the Digestive Tract peristalsis sphincters Mouth esophagus stomach small intestine large intestine rectum anus Peristalsis wavelike muscular contractions of the GI tract that push the contents Sphincter circular muscle surrounding and able to close a body opening o Keeps the flow of food in one direction Absorption Most absorption occurs in the small intestine Fibers are not absorbed and continue through the digestive tract Structure and Characteristics of Lipids Proteins and Carbohydrates CHO o Monosaccharides Single sugars Simple o Disaccharides Pairs of mono Simple o Polysaccharides Large Chains of mono Complex Lipids o Tyiglycerides o Phospholipids o Sterols Proteins o Proteins are made up of amino acids o Amino acids contain nitrogen N carbon C hydrogen o H and oxygen O o All amino acids have the same basic structure o Central carbon atom o Hydrogen atom o Acid group COOH o Amino Group NH2 o Side group varies with each amino acid Functions of the Macronutrients CHO o Glycogen is the primary source of energy for cells Lipids o Part of every cell membrane o Energy o Insulation of body temp o Protection to vital organs Proteins o Structural o Enzymes o Hormones o Regulators of fluid balance o Acid case regulators o Transporters o o Antibodies Source of energy and glucose Digestion process of each macronutrient CHO o DIGESTION o Mouth o Salivary enzyme amylase hydrolyzes starch into smaller o molecules shorter polysaccharides or maltose o Stomach o No new enzymes are introduced to break down CHO o Salivary amylase diminishes as stomach acid and proteindigesting o enzymes break it down o Fiber may promote satiety o Small Intestine o Pancreatic amylase continues breaking down polysaccharides o Final digestion takes place on outer membranes of intestinal o cells o Maltase o Breaks maltose into 2 glucose molecules o Sucrase o Breaks sucrose into glucose and fructose o Lactase o Breaks lactose into glucose and galactose o Mostly glucose molecules remain o Large Intestine o Fibers remain and attract water o Bacteria in GI tract ferment some fibers mainly soluble o Generates water and gas o Fibers do contribute a small amount of energy for the colon 2kcal g o ABSORPTION o Primarily takes place in the small intestine o Active transport o Glucose and galactose o Facilitated diffusion o Fructose o Fructose and galactose are metabolized by the liver o Glucose sent to body s cells for energy Lipids o DIGESTION o Challenge is to keep the lipids mixed vs separation o Lipids hydrophobic o Digestive enzymes are hydrophilic o Mouth o Some hard fats melt o Stomach o Muscles contract to propel contents toward pyloric sphincter o Lipid particles broken down by gastric lipase o Small Intestine o When fat enters cholecystokinin CCK is released which o signals the release of bile from the gallbladder o Bile acts as an emulsifier so the enzymes can act on the fat o Most fat digestion occurs in the small intestine o Pancreatic lipases and intestinal lipases o ABSORPTION o Glycerol and short and medium chain fatty acids o absorbed directly into the bloodstream o Monoglycerides and long chain fatty acids form o micelles spherical complex o Transported by proteins called chylomicrons o Lipid transport is made possible by a group of vehicles o known as lipoproteins o Chylomicrons o Largest of the lipoproteins o Least dense o Get smaller as triglycerides are removed by the cells o Very Low Density Lipoproteins VLDL o Composed primarily of triglycerides o Transport lipids to the tissues o Get smaller and more dense as triglycerides are removed and VLDL o becomes an LDL o Low Density Lipoproteins LDL o Composed primarily of cholesterol with few triglycerides o Transport lipids to the tissues o High Density Lipoprotein HDL o Composed primarily of protein o Transport cholesterol from the cells to the liver o Health Implications o High LDL is associated with higher risk of heart disease and o known as bad cholesterol o High HDL appears to have a protective effect Protein o DIGESTION o Mouth o Proteins are crushed and moistened o Stomach o Partial breakdown of protein through hydrolysis o Hydrochloric acid uncoils denatures proteins o Small Intestine o Polypeptides enter the SI o Pancreatic and intestinal proteases hydrolyze them into smaller o o o o o o o o o o peptide chains and single amino acids Peptidases on the intestinal wall split most dipeptides and tripeptides into single amino acids ABSORPTION Specific carriers transport amino acids into intestinal cells Once in the cell they may be used for energy or to synthesize needed compounds Amino acids not used by intestinal cells are transported across the cell membrane Then sent to the