Q&A Hero

Q: What is a likely reason that large quantities of fructose may cause gut discomfort? a. Diffusion of fructose only occurs from low to high concentrations. b. Facilitated diffusion is slower than active transport. c. Active transport is saturable. d. Pinocytosis reverses fructose and releases it to the gut.

Q: Choose the best description of the main method of glucose absorption. a. passive diffusion down a concentration gradient b. active transport with fructose c. facilitated transport d. active transport with sodium

Q: The final molecules that are absorbed from the digestion of the carbohydrate in spaghetti (noodles) and a cream sauce are _____. 1) sucrose 2) glucose 3) maltose 4) galactose 5) lactose 6) fructose a. 1, 4 b. 1, 4, 6 c. 1, 5, 3 d. 2, 4

Q: Sucrose digestion is initiated in the _____. a. pylorus b. fundus c. duodenum d. mouth

Q: The disaccharidases are synthesized by the _____. a. pancreas04 b. liver c. enterocyte d. chief cell

Q: The enzyme needed to hydrolyze the α (1,6) bond of amylopectin is _____, which is secreted from the _____. a. amylase, enterocyte b. sucrase, pancreas c. lactase, enterocyte d. isomaltase, enterocyte

Q: Which of the following is the predominant monosaccharide produced by the digestion of all dietary carbohydrates? a. ribose b. fructose c. galactose d. glucose

Q: Which of the following carbon bonds is digested by α-amylase? a. α (1-4) b. α (1-6) c. β (1-4) d. β (1-6)

Q: What is the key enzyme in digestion of polysaccharides? a. starch amylopectin b. β-amylase c. α-dextranase d. α-amylase

Q: In what form do carbohydrates enter the bloodstream? a. starch b. disaccharides c. monosaccharides d. ketoses

Q: A homopolysaccharide that is important in human diets is _____ and the end product formed from the complete digestion of this homopolysaccharide is _____. a. cellulose; glucose b. lactose; galactose c. glycogen; glucose d. starch; glucose

Q: Which of the following homopolysaccharides made of glucose contributes the most energy to the ordinary diet? a. amylose b. amylopectin c. glycogen d. cellulose

Q: What is the most common digestible homopolysaccharide existing as both amylose and amylopectin? a. glycogen b. cellulose c. hemicellulose d. starch

Q: What are the major dietary energy sources that are composed of two simple sugars? a. disaccharides b. polysaccharides c. monosaccharides d. trioses

Q: Name the model that depicts cyclized monosaccharides as lying in a horizontal plane with the hydroxyl groups pointing down or up from the plane. a. Haworth b. Fischer projection c. cyclized Fischer projection d. stereoisomer

Q: What is the nutritional significance of stereoisomers? a. Some isomers cannot cyclize. b. Certain metabolic enzymes require a particular structure. c. Certain isomers cannot polarize light. d. Some isomers have no anomeric carbon.

Q: When compounds with 1 or more chiral carbon atoms and the same formula are arranged as mirror images they are said to be _____. a. symmetrical b. enantiomers c. rotated d. linear

Q: A ketopentose is a carbohydrate containing a. 5 carbons and a ketone group. b. 6 carbons and an aldehyde group. c. 3 carbons and an aldehyde group. d. 7 carbons and a ketone group.

Q: The majority of energy in the typical American diet comes from: a. fat. b. protein. c. carbohydrate. d. vitamins.

Q: What causes the diarrhea associated with pancreatitis?

Q: Name 4 grains that can cause severe discomfort in people with celiac disease. What are the proteins that are problematic in each grain?

Q: Why are water-miscible fat-soluble vitamins recommended for individuals with Crohn's disease?

Q: Discuss the role of high-fat foods, chocolates, peppermint, and smoking in gastroesophageal reflux disease.

Q: Discuss the functions and significance of the folds of Kerckring, the villi, and the microvilli.

Q: Bariatric surgery involves removal or bypass of a large portion of the stomach. Speculate on how the production of ghrelin following bariatric surgery might affect appetite and explain your reasoning.

Q: If psychological stress increases the output of norepinephrine from the sympathetic nervous system and epinephrine from the adrenal gland, predict the ways in which digestion may be affected.

Q: Discuss three of the five mechanisms by which probiotics may be helpful in diarrheal illnesses.

Q: What are probiotics and prebiotics? Give examples of each.

Q: Develop a hypothesis regarding the effects of a wide-spectrum antibiotic on the beneficial effects of gut flora.

Q: Describe the mechanisms by which resin-type drugs and functional foods containing phytostanols lower high blood cholesterol levels.

Q: What happens to reabsorbed bile acids after transport back to the liver?

Q: Describe the effect of starvation on immunological defense/barriers in the gastrointestinal tract and the possible consequences.

Q: Discuss the role of drug therapies such as Tagamet, Zantac, and Pepcid in the treatment of peptic ulcers.

Q: Provide the appropriate information for four regulatory peptides in the following table.Information in each row must match.Name of the peptideProduction site(s)Major action(s)5) somatostatin6) cholecystokinin7) secretin8) gastrin

Q: The proximal colonic epithelial cells absorb water and the major cation _____. In contrast, potassium and the anion _____ are secreted into the lumen of the colon.

Q: Owing to the alkaline pH of bile, the conjugated bile acids combine with _____, _____, or _____ to form bile salts.

Q: Bile acids are conjugated with amino acids, _____ and _____, to make them more useful in forming micelles.

Q: In the hepatocyte, cholesterol is _____ into the two primary bile acids, _____ and _____ acids.

Q: You"ve just read an article about a newly discovered nutrient that is water soluble. What can you predict about how it is absorbed and transported in the body? If instead this new nutrient were lipid soluble, how would these processes be different? To answer this, match three terms with each type of nutrient solubility.Term1) passive diffusion2) lymphatic system3) capillaries in villi4) chylomicron5) active/facilitated transportType of solubilitya. water-solubleb. lipid-soluble

Q: Digestion: From the following list shown in the box, choose the best answer and place the corresponding letter on the blank for each statement. You can only use an answer choice (letter) oncesome you won"t use at all.a. amylose b. saliva c. HCl d. -1,4-bonds e. cholecystokinin f. -1,6-bonds g. bile h. amylase i. pancreas j. lipase k. trypsin l. zymogen m. liver n. gastrin o. stomach p. amylopectin q. secretin r. pepsinogen(1)_____ is the regulatory peptide that is responsible for acid release from the (2)_____, whereas (3)_____ stimulates the gallbladder to release (4)_____.A protease secreted in the stomach is (5)_____, which is released in its (6)_____ form that must be activated by the action of (7)_____.The enzyme (8)_____ can be found in both (9)_____ (a little) and the (10)_____ (the majority), and is responsible for the digestion of triglycerides.The enzyme 1(1)_____ is responsible for the digestion of polysaccharides.

Q: Match the substance important for digestion with its site of production.Molecule1) pepsinogen2) trypsinogen3) ptyalin4) digestive glycoproteins5) cholic acidSite of productiona. hepatocytesb. gastric chief cellsc. pancreatic exocrine tissued. salivary glandse. small intestine

Q: Neural and hormonal events affect the activities of the GI tract. These can be classified as stimulatory or inhibitory. For questions 56-62, choose "a" if the action described is stimulatory and "b" if it is inhibitory.Ghrelin on satiety

Q: Neural and hormonal events affect the activities of the GI tract. These can be classified as stimulatory or inhibitory. For questions 56-62, choose "a" if the action described is stimulatory and "b" if it is inhibitory.Eating a meal on ghrelin secretion

Q: Neural and hormonal events affect the activities of the GI tract. These can be classified as stimulatory or inhibitory. For questions 56-62, choose "a" if the action described is stimulatory and "b" if it is inhibitory.GIP on the release of a hormone from the pancreatic β-cells

Q: Neural and hormonal events affect the activities of the GI tract. These can be classified as stimulatory or inhibitory. For questions 56-62, choose "a" if the action described is stimulatory and "b" if it is inhibitory.CCK on the release of bile

Q: Neural and hormonal events affect the activities of the GI tract. These can be classified as stimulatory or inhibitory. For questions 56-62, choose "a" if the action described is stimulatory and "b" if it is inhibitory.Leptin secretion on desire to eat

Q: Neural and hormonal events affect the activities of the GI tract. These can be classified as stimulatory or inhibitory. For questions 56-62, choose "a" if the action described is stimulatory and "b" if it is inhibitory.CCK on pancreatic zymogen release

Q: Neural and hormonal events affect the activities of the GI tract. These can be classified as stimulatory or inhibitory. For questions 56-62, choose "a" if the action described is stimulatory and "b" if it is inhibitory.Secretin on HCl release

Q: All of the following are involved in satiety and suppression of food intake EXCEPT _____. a. cholecystokinin b. corticotropin-releasing hormone c. neuropeptide Y d. leptin

Q: Which of the following peptides stimulates appetite? a. bombesin b. ghrelin c. leptin d. cholecystokinin

Q: Which regulatory peptide synthesized in the pancreatic and intestinal cells appears to inhibit release of gastrin, secretin, and motilin? a. neurotensin b. GRP c. insulin d. somatastatin

Q: Secretin is released from the enteroendocrine S-cell in the _____. a. proximal small intestine b. gastric mucosa c. esophagus d. colon

Q: The major role of gastrin in the GI tract is that of _____. a. inhibition b. stimulation c. transport d. no effect

Q: Among the regulatory peptide molecules, some are recognized as true hormones. Which of the following is a paracrine rather than a hormone? a. somatostatin b. secretin c. cholecystokinin d. gastrin

Q: The neuronal network system located in the submucosa (plexus of Meissner) controls: a. peristalsis and local blood flow. b. ileal secretions and gastric motility. c. frequency and strength of gastric muscle contractions. d. gastrointestinal secretions and local blood flow.

Q: The parasympathetic nervous system affects gastrointestinal motility by a. stimulating peristalsis. b. constricting sphincters. c. decreasing muscle contractions. d. inhibiting peptide production.

Q: Prebiotics act as substrates for the growth of beneficial bacteria in the colon and are _____. a. certain types of bifidobacteria b. live cultures of mixed lactobacilli c. selected fibers d. antibiotics

Q: Lactose intolerance is common in all of the following EXCEPT _____. a. European Americans b. African Americans c. American Indians d. Asian Americans

Q: When diagnosing lactose intolerance, _____ is measured in the breath following oral consumption of 50 g lactose. a. methane b. hydrogen c. carbon dioxide d. sulfur

Q: What percentage of urea produced in the body is converted to ammonia by bacteria in the colon and reabsorbed? a. 10% b. 25% c. 50% d. 100%

Q: Anaerobic bacteria populate the gut in _____ greater quantities than aerobic bacteria. a. 2 fold b. 5 fold c. 10 fold d. 100 fold

Q: Of the 3 short-chain fatty acids created by gut bacteria, which one is the preferred energy source for colonic epithelial cells? a. butyric acid b. acetic acid c. propionic acid d. oleic acid

Q: One of the major molecules absorbed from the colon is water and one liter of chyme entering the large intestine is normally reduced to _____. a. 500 g b. 400 g c. 300 g d. 200 g

Q: Which hormone is responsible for decreasing sodium absorption in the colon? a. glucocorticoids b. mineralcorticoids c. vasopressin d. glucagon

Q: Which of the mechanisms responsible for absorption of nutrients into the epithelial cell of the villus requires energy? a. diffusion b. facilitated diffusion c. active transport d. pinocytosis

Q: How long does it take for most of the carbohydrate, protein, and fat to be absorbed from chyme after it enters the small intestine? a. 10 minutes b. 30 minutes c. 1 hour d. 2 hours

Q: In general, in which portion of the gastrointestinal tract does most absorption occur? a. esophagus b. stomach c. small intestine d. colon

Q: Which of the following is enterohepatically circulated? a. pancreatic enzymes b. bile c. glucose d. CCK

Q: What percentage of cholesterol in bile is used to form chylomicrons? a. none of it b. 10% c. 25% d. 50%

Q: The total bile acid pool in the human body is 2.5 to 5 g. What percentage of bile is reabsorbed in the ileum? a. 10% b. 30% c. 65% d. 90%

Q: Conjugation of bile acids with glycine and taurine improves their ability to a. ionize and form micelles. b. undergo enterohepatic recirculation. c. be excreted in the feces, thus keeping serum cholesterol normal. d. promote the formation of bile salts.

Q: Bile salts are synthesized from cholesterol in the _____. a. canaliculi b. common bile duct c. hepatocytes d. gallbladder

Q: The hormone primarily responsible for contraction of the gallbladder and release of bile into the duodenum is _____. a. gastrin b. secretin c. cholecystokinin d. GRP

Q: Which enzyme or zymogen is secreted from the pancreas? a. pepsinogen b. enterokinase c. procarboxypeptidases d. maltase e. acyl-CoA synthetase

Q: The hormone whose major action is to alkalize intestinal contents by stimulating secretion of bicarbonate from the pancreas and by inhibiting gastric acid secretion and gastric emptying is _____. a. gastrin b. secretin c. cholecystokinin d. GRP

Q: In what organ are enzymes produced that are responsible for digestion of 50% of carbohydrate and protein and 90% of fat? a. liver b. esophagus c. pancreas d. gallbladder

Q: The majority of the pancreatic tissue is _____. a. endocrine in function b. exocrine in function

Q: Pancreatic juice that enters the duodenum through the sphincter of Oddi contains all of the following EXCEPT _____. a. digestive enzymes b. intrinsic factor c. anions such as bicarbonate and chloride d. cations such as sodium, potassium, and calcium

Q: The pancreas is a digestive system accessory organ with two types of active tissue, the ductless endocrine cells that secrete insulin and glucagon and the a. liver-like cells that produce bile. b. ductless absorptive tissue that controls bicarbonate. c. acinar exocrine cells that produce digestive enzymes. d. erythropoietic cells that produce red blood cells.

Q: Choose the phrase that best describes the function of the crypt of Lieberkhn. a. mucus secretion b. glucose oxidation c. cellular differentiation d. amylase secretion