Exam 2 Study Guide1. What are the roles of food type on hunger? - Proteins have the highest satiety value (will feel satiated for longer)- High-fat diets have a higher satiety value than high-carbohydrate diets- Bulky meals (high in fibers and water) distend the stomach and promote a sense of satiety - Solid foods are more filling than semisolid foods or liquids 2. Define the processes of digestion, absorption, and elimination as well as how digested food is moved throughout the digestive tract.- Digestion: large food molecules are broken down to smaller molecules, mechanicallyand chemically - Absorption: process of taking these products through the intestinal wall- Elimination: undigested portions of food and waste products are removed from the body - Gastrointestinal (GI) Tract: a series of organs arranged in a long tube that work together to process foods. - Sphincters: muscles that control the passage of food material from one GIT organ to the next. 3. Know the enzymes and hormones of digestion- Gastrin: a hormone secreted by stomach lining cells that stimulates the gastric juice - Gastric juice contains:o Hydrochloric acid (HCI): helps break apart food particles and also destroys any germs on foodo Pepsin: enzyme to digest proteino Gastric lipase: enzyme to digest fato Intrinsic factor: protein to absorb vitamin B12 o Gastrin: hormone stimulated by Hydrochloric acid that encourages the secretion of gastric juice to promote digestiono Secretin: hormone that slows down the production of gastric juice and helps to stimulate the release of pancreatic juice o Cholecystokinin (CCK): hormone that inhibits stomach emptying and stimulates the continuous release of pancreatic juice and bile into the duodenum. This hormone helps you feel full. o Gastric inhibitory peptide (GIP): inhibits gastric acid secretion, slows gastric emptying, and stimulates insulin release 4. Know the two different types of cells in gastric glands and their functions- Parietal cells: secrete HCI and intrinsic factor- Chief cells: secrete pepsinogen and gastric lipase5. List the accessory organs that facilitate digestion and their roles.- Gallbladdero Stores bile (a yellow-brownish liquid that is made in the liver and stored in the gallbladder and is used to break down fat)o CCK signals the gallbladder to release bile o Bile emulsifies the lipids Lipids are dispersed into smaller globules and become more accessible to digestive enzymes- Pancreaso Manufactures, holds, and secretes digestive enzymes o Stores enzymes in the inactive form Pancreatic amylase digests carbohydrates Pancreatic lipase digests fats Protease digests proteins o Insulin and glucagon (hormones) are produced to regulate blood glucoseo Bicarbonate (prevents blood from becoming too acidic) is secreted to neutralize chyme (liquidy form of food after it is digested) - Liver: one of the most important organs in the body o Synthesizes chemicals for metabolism Bile for emulsification of fats o Receives the products of digestion via the portal veino Releases glucose from glycogen storeso Stores vitaminso Manufactures blood proteinso Filters the blood, removing wastes and toxins 6. What is a food intolerance vs. a food allergy.- Food intolerance: gastrointestinal discomfort caused by certain foods that is not a result of an immune system reaction - Food allergy: an allergic reaction to food, caused by a reaction in the immune system7. Define lactose intolerance.- You are not fully able to digest the milk sugar (lactose) in dairy products- Lactase: enzyme in the small intestine that breaks down lactose into simpler sugar forms- Do not produce enough lactase - Undigested lactose sits in the stomach and gets broken down by bacteria which causes gas, bloating, stomach cramps, and diarrhea 8. Define the role of mouth, pancreas, stomach, gallbladder, and liver in macronutrient digestion (know all the steps for carbs, fats, and proteins)- Carbohydrateso Mouth salivary amylase (enzyme) breaks down carbs down to maltose o Pancreas- secretes beta cells which secretes insulin secretes alpha cells which secrete glucagon; pancreatic amylase (enzyme) is secreted into the small intestine to digest carbs to maltose.o Stomach chemical digestion does not occur here Most occurs in the small intestineo Gallbladder nothing o Liver monosaccharides travel here via portal vein They are converted to glucose. T then they are transported to body cells to provide energy - Fat o Mouth very little digestion occurs. Lingual lipase secreted by tongue cells and mixed with saliva digests some triglycerides o Pancreas produces lipid digesting enzymes which are released into the small intestine break fat into 2 fatty acids and a monoglycerideo Stomach fat is mixed and broken into droplets. Gastric lipase digests some triglycerideso Gallbladder bile is stored here and then released into the small intestineo Liver produces bile which is then stored in the gallbladder - Proteins o Mouth crushed by chewing and moistened by saliva o Pancreas proteases (enzyme) completes protein digestion o Stomach begins here Hydrochloride acid denatures protein strands and activates pepsin. Pepsin (enzyme) breaks down proteins into short polypeptides and amino acids. Gastrin (hormone) controls hydrochloric acid production and pepsin release o Gallbladder nothingo Liver- amino acids are transported from small intestine to here they are converted to glucose or fat which is used for energy or to build new proteins, or sent to the cells as needed 9. What hormones regulate blood glucose levels - Insulino Secreted by beta cells of the pancreaso Stimulates glucose transporters (carrier proteins) to help tale glucose from the blood across the cell membraneo Stimulates the liver to take up glucose and convert it to glycogeno When blood glucose levels increase after a meal, the pancreas secretes the hormone insulin from the beta cells into the blood stream- Glucagono Secreted by alpha cells of the pancreaso Stimulates the liver to convert glycogen to glucose o Stimulates gluconeogenesis, the production of glucose from amino acidso When blood glucose levels are low, the pancreas secretes the hormone glucagon from the alpha cells into the blood stream10. Define glycemic index and glycemic load.- Glycemic index: indicates how rapidly a carb is digested and released as glucose (sugar) into the blood stream. In
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