Exam 2 Study Guide 1 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 mechanically and 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 food o Pepsin enzyme to digest protein o Gastric lipase enzyme to digest fat o Intrinsic factor protein to absorb vitamin B12 o Gastrin hormone stimulated by Hydrochloric acid that encourages the secretion of gastric juice to promote digestion o 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 lipase 5 List the accessory organs that facilitate digestion and their roles Gallbladder o 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 Pancreas o 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 glucose o 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 vein o Releases glucose from glycogen stores o Stores vitamins o Manufactures blood proteins o 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 system 7 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 Carbohydrates o Mouth o Pancreas salivary amylase enzyme breaks down carbs down to maltose 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 chemical digestion does not occur here Most occurs in the small intestine o Stomach o 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 produces lipid digesting enzymes which are released into the small o Pancreas intestine o Stomach o Gallbladder break fat into 2 fatty acids and a monoglyceride fat is mixed and broken into droplets Gastric lipase digests some triglycerides bile is stored here and then released into the small intestine produces bile which is then stored in the gallbladder crushed by chewing and moistened by saliva proteases enzyme completes protein digestion begins here Hydrochloride acid denatures protein strands and activates pepsin o Liver Proteins o Mouth o Pancreas o Stomach Pepsin enzyme breaks down proteins into short polypeptides and amino acids Gastrin hormone controls hydrochloric acid production and pepsin o Gallbladder release nothing o 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 Insulin o Secreted by beta cells of the pancreas o Stimulates glucose transporters carrier proteins to help tale glucose from the blood across the cell membrane o Stimulates the liver to take up glucose and convert it to glycogen o When blood glucose levels increase after a meal the pancreas secretes the hormone insulin from the beta cells into the blood stream Glucagon o Secreted by alpha cells of the pancreas o Stimulates the liver to convert glycogen to glucose o Stimulates gluconeogenesis the production of glucose from amino acids o When blood glucose levels are low the pancreas secretes the hormone glucagon from the alpha cells into the blood stream 10 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 other words how quickly foods break down into sugar in your bloodstream A good with a high GI raises blood sugar more than a food with a medium to low GL Glycemic load a ranking system for a carbohydrate rich food that measures the
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