METABOLISM EXAM 1 1 proteins attached to the membrane through hydrophobic interactions and embedded in the membrane are called INTEGRAL PROTEINS 2 The pancreas is a digestive system accessory organ with two types of active tissue the ductless endocrine tissue that secretes and Glucagon and insulin and the ducted exocrine tissue that produces digestive enzymes 3 Pyruvate is an example of a triose found in the glycolytic pathway 4 The organelle that serves as the digestive system or recycling center for the cell is the lysosome 5 Most of the digestive enzymes produced by the intestinal mucosal cells i e enterocytes function at the brush border 6 What cells found in both the oxyntic glands and the pyloric glands of the stomach secrete hydrochloric acid and intrinsic factor Parietal cells 7 In what form do carbohydrates enter the systemic circulation MONOSACCHARIDES 8 The major role of gastrin in the stomach is that of STIMULATION OF HCL SECRETION 9 Glycemic load considers the QUANTITY OF CARBOHYDRATE in the food 10 In general in which portion of the gastrointestinal tract does the most absorption occur SMALL INTESTINE 11 The major end products of the complete cellular oxidation of carbohydrate include WATER CARBON DIOXIDE and ENERGY 12 Which of the mechanisms responsible for the absorption of nutrients into an epithelial cell requires energy ACTIVE TRANSPORT 13 Two hormones that stimulate glycogenolysis in the muscle and liver are GLUCAGON and EPINEPHRINE 14 The hormone primarily responsible for the contraction of the gallbladder and subsequent release of bile into the duodenum is CHOLECYSTOKNIN 15 What is the likely reasons that large quantities 50g fructose may cause gut discomfort FACILLIATED DIFFUSION IS SLOWER THAN ACTIVE TRANSPORT 16 All of the following are substrate for gluconeogenesis except FATTY ACIDS 17 Which of the following is the primary gluconeogenic tissue LIVER 18 Bile is the most important for the digestion and absorption of FATS 19 A function of hydrochloric acid in the gastric juice is to ACT AS A BACTERICIDAL AGENT 20 The hormone whose major action is to alkalize contents in the intestinal lumen stimulating secretion of bicarbonate from the pancreas and by inhibiting gastric acid secretion and gastric emptying is SECRETIN 21 What tissue specific enzyme is responsible for the digestion of most carbohydrate Pancreatic alpha amylase 22 What is the storage form of digestible carbohydrate in plants STARCH 23 What is the storage form of carbohydrate as carbohydrate in humans GLYCOGEN 24 Provide one example of a specific nutrient that is absorbed into the portal circulation GLUCOSE 25 Glucose is transported across the apical or luminal membrane of the enterocyte by SGLT1 26 Fructose is transported across the apical or luminal membrane of the enterocyte by GLUT5 27 The major source of energy in the typical American diet comes fromwhich class or category of macronutrients CARBOHYDRATES 28 Into what portion of the gastrointestinal tract are bile salts secreted DUODENUM 29 Under aerobic conditions there are 6 mol of pyruvate produced per 3 mol of glucose 30 Name two foods or food products that are capable of decreasing lower esophageal sphincter pressure Chocolate peppermint 31 Name one of the three rate limiting irreversible enzymes of glycolysis PFK phosphofructokinase 32 Briefly explain the importance of the enzyme glucose 6 phosphate in terms of the metabolism of carbohydrate and the maintenance of plasma glucose in the liver and skeletal muscle The liver contains the enzyme G 6 Pase but he skeletal muscle does not During a fed state both the liver and skeletal muscle will take in glucose and store it as glycogen During fasting the liver breaks down glycogen to glucose 6 phosphate G 6 Pase dephoshorylates the G 6 P so that it can go into circulation to be used for other tissues in the body Skeletal muscle does not have G 6 Pase so glycogen is droken down into G 6 P to be used in that time 33 Compare and contrast glucose transport at both the apical and basolateral membrane of enterocytes At the apical membrane glucose is brought into the enterocyte by SGLT 1 which uses the Na K ATPase pump By symport the tow NA molecules coming in provide energy for glucose to be transported At the basolateral membrane glucose is transportedto the blood by GLUT2 which works by faciliiated diffusion Glucose can passively diffuse in and out of the enterocyte but this is very rare 34 Predicat and explain the physiological outcome that would result if the brain expressed GLUT2 instead of GLUT 3 under euglycemic and hypoglycemic conditions GLUT 2 km of 15 20mM has a much lower affinity for glucose than GLUT 3 km of 1 mM If the brain expressed GLUT 2 it would only transport glucose into its cells during fed states when blood sugar was high During euglycemia km 5mM and hypoglycemia 2 8mM the brain would nto transport enough glucose into its cells and would go into a coma 35 List two pancreatic digestive enzymes and identify or dexcribe their specific substrates Pancreas alpha amylase digests starches such as amylase and the alpha 1 4 bonds of amylopectin but not of 1 6 pancreatic lipase lipids with chains less than 18 carbons TAG Carbohydrates Simple sugars Monosaccharides and Disaccharides Glucose Fructose and Galactose Maltose Lactose and Sucrose Carbohydrates Oligosaccharides and Polysaccharides Stachyose Raffinose Verbacose Starch or Glycogen Amylose Amylopctin Fiber and Resistant Glycosaminoglycans Chondrotin sulfate hyaluronic acid Starch Cellulose Pectin Hemicellulose What happens when you eat skittles then hideaway When chewing salivary alpha amylase begins to break down the CHOs The bolus moves down the esophagus to the stomach where alpha amylase stops working due to a low pH It is moved to the small intestine where pancreatic alpha amylase breaks it down into disaccharides SGLT 1 brins in glucose and GLUT 5 brings in fructose into the enterocyte GlUT2 transports them out of the basolateral membrane into the blodd where it goes to the liver After the pizza blood sugar would be high and insulin would be relased and uptake into muscle and adipose tissue would occur The liver would also take in glucose Glycolysis and glycogenesis would be stimulated Gluconeogenesis and glycogenolysis would be repressed The CHO from the skittles would be stored as glycogen first and then fatty acid synthesis would occur hexose monophosphate shunt Email to ellie sparks okstate edu Andrea callahan