Which of the following statements is TRUE regarding the emulsification of fats?
A. Fat emulsification requires pancreatic lipase.
B. Emulsification is the splitting of triglycerides into monoglycerides and free fatty acids.
C. Fat emulsification occurs mainly in the liver.
D. Emulsification is the production of a chylomicron from triglycerides and protein.
E. Fat emulsification requires secretion of bile salts and phospholipids by the liver.
(
Question 2) Which accurately describes lipase?
A. It is mainly produced in the liver, and secreted into the small intestine.
B. It emulsifies lipids.
C. It is secreted by the endocrine pancreas.
D. It is produced in the exocrine pancreas, and catalyzes the degradation of chylomicrons into proteins and fats.
E. It catalyzes the breakdown of triglycerides into monoglycerides and free fatty acids.
(
Question 3) Which of the following statements about the transport of the absorbed products of fat digestion is TRUE?
A. Free fatty acids and monoglycerides are transported to the liver via the hepatic portal vein.
B. Products of fat digestion first go to the lymph system, and then to the veins leading to the heart.
C. Triglycerides are transported to the liver via the hepatic portal vein to be processed.
D. Free fatty acids and monoglycerides are assembled into triglycerides before they are absorbed from the lumen of the gut into epithelial cells lining the tract.
E. Products of fat digestion are absorbed in the distal portion of the ileum, bound to intrinsic factor.
(
Question 4) The main source of enzymes that cleave disaccharides into monosaccharides is:
A. the pancreas.
B. the liver.
C. gastric secretory cells.
D. the luminal membrane of epithelial cells in the small intestine.
E. the salivary glands.
(
Question 5) Which of the following molecules crosses the luminal membrane of intestinal cells by facilitated diffusion?
A. glucose
B. lactose
C. fructose
D. galactose
E. maltose
(
Question 6) Which of the following statements regarding digestion and absorption of carbohydrates is TRUE?
A. Carbohydrate digestion begins in the stomach.
B. Lactose intolerance results from an insufficiency of the enzyme amylase.
C. Digestible polysaccharides are broken down into the monosaccharides glucose, galactose, and fructose, which can be absorbed.
D. Sucrose is the main form of carbohydrate that can be absorbed by active transport across the intestinal epithelium.
E. Cellulose from plants is a polymer of glucose that can be easily digested and absorbed by the human GI tract.
(
Question 7) Which of the following enzymes is most active at an acidic pH?
A. amylase
B. lipase
C. trypsin
D. pepsin
E. chymotrypsin
(
Question 8) What structure secretes the enzyme that breaks down starch to smaller carbohydrates?
A. the esophagus
B. pancreatic exocrine cells
C. pancreatic duct cells
D. the liver
E. the large intestine
(
Question 9) Which is NOT a function performed by saliva?
A. moistening and lubricating food for swallowing
B. starch digestion
C. enabling the sense of taste
D. killing bacteria
E. emulsifying lipids
(
Question 10) Which correctly describes a major function of the stomach?
A. the complete digestion of protein to amino acids
B. maintaining an alkaline pH for the digestion of proteins
C. absorption of saliva and chyme into the bloodstream
D. lubricating food so it can be formed into a bolus
E. storing ingested food and partially digesting macromolecules