Problem Set 4
Digestive secretions with a pH of 2 are characteristic of the:
A. small intestine B. stomach C. pancreas D. mouth
Pepsin is a digestive enzyme that:
A. is manufactured by the pancreas. B. helps stabilize fat-water emulsions. C. splits maltose into monosaccharides. D. begins the hydrolysis of proteins in the stomach. E. is denatured and rendered inactive in solutions with low pH.
In the digestive system, peristalsis is:
A. a process of fat emulsification in the small intestine. B. voluntary control of the rectal sphincters regulating defecation. C. the transport of nutrients to the liver through the hepatic portal vessel. D. a common cause of loss of appetite, fatigue, and dehydration. E. smooth muscle contractions that move food along the esophagus
Certain nutrients are considered "essential" in the diets of some animals because:
A. only those animals use those nutrients. B. the nutrients are subunits of important polymers. C. these animals are not able to synthesize these nutrients. D. the nutrients are necessary coenzymes. E. only certain foods contain them.
Because the foods eaten by animals are often composed largely of macromolecules, this requires the animals to have mechanisms for:
A. elimination C. enzymatic hydrolysis B. dehydration synthesis D. regurgitation
The bile salts:
A. are enzymes. B. are manufactured by the pancreas. C. emulsify fats in the duodenum. D. increase the efficiency of pepsin action. E. are normally an ingredient of gastric juice.
After ingestion by humans, the first category of macromolecules to be chemically digested by enzymes in the mouth is:
A. proteins C. cholesterol and other lipids B. carbohydrates D. nucleic acids
The absorption of fats differs from that of carbohydrates in that the:
A. processing of fats does not require any digestive enzymes, whereas the processing of carbohydrates does.
B. fat absorption occurs in the stomach, whereas carbohydrates are absorbed from the small intestine.
C. carbohydrates need to be emulsified before they can be digested, whereas fats do not.
D. most absorbed fat first enters the lymphatic system, whereas carbohydrates directly enter the blood.
E. fats, but not carbohydrates, are digested by bacteria before absorption.
If you were to jog 3 miles a few hours after lunch, which stored fuel would you probably tap?
A. muscle proteins C. muscle and liver glycogen B. fat stored in the liver D. liver proteins
For a nondiabetic person, the glucose concentration in this part of the vasculature varies more than in any other part:
A. abdominal artery C. pulmonary veins B. coronary arteries D. hepatic portal vessel
After surgical removal of an infected gallbladder, a person must be especially careful to restrict dietary intake of: A. starch B. protein C. salt D. fat
Complex nutrients are digested and then absorbed into the lymph or bloodstream as: A. disaccharides B. polymers C. monomers D. peptides
After eating a carbohydrate-rich meal, the mammalian pancreas increases its secretion of: A. glucagon C. insulin B. pepsin D. secretin
A group of animals among which a relatively long cecum is likely to be found is the: A. carnivores B. herbivores C. autotrophs D. omnivores
Ingested dietary substances must cross cell membranes to be used by the body, a process known as: A. ingestion B. digestion C. hydrolysis D. absorption
Constipation can result from the consumption of a substance that:
A. contains plenty of fiber. B. promotes water reabsorption in the large intestine. C. speeds up movement of material in the large intestine. D. decreases water reabsorption in the small intestine. E. stimulates peristalsis.
Stomach cells are moderately well adapted to the acidity and protein-digesting activities in the stomach by having:
A. a sufficient colony of H. pylori. B. a thick, mucous secretion and active mitosis of epithelial cells. C. a high level of secretion by chief cells. D. a high level of secretion from parietal cells. E. secretions enter the stomach from the pancreas.
Ghrelin, a hormone secretes by the stomach, functions to:
A. triggers a feeling of hunger before meals to increase appetite. B. suppress appetite after a meal. C. triggers the release of pancreatic juice to regulate digestion. D. inhibits peristalsis in the stomach to slow down digestion. E. regulate stomach pH to inhibit gastric juice secretion.
A fasting animal whose energy needs exceed those provided in its diet draws on its stored resources in which order? A. fat, then glycogen, then protein. B. glycogen, then protein, then fat. C. liver glycogen, then muscle glycogen, then fat. D. muscle glycogen, then fat, then liver glycogen. E. fat, then protein, then glycogen.
A. a digestive enzyme secreted by the pancreas to breakdown polypeptides. B. a hormone secreted by the pancreas to enhance appetite. C. a hormone secreted by the small intestine to trigger the release of pancreatic juice and bile salt. D. a hormone secreted by the small intestine to promote stomach peristalsis. E. a digestive enzyme secreted by the small intestine to breakdown DNA & RNA.