Question 1

Pancreatic enzymes cannot catalyze the complete digestion of dietary proteins to amino acids in the intestine because

Accepted Answer

A)  pancreatic proteases are zymogens. 
B)  the pH in the small intestine is unfavorable for activity of pancreatic proteases. 
C)  pancreatic proteases are endopeptidases. 
D)  bacteria destroy pancreatic proteases in the small intestine. 
E)  pepsin from the stomach is required to activate pancreatic proteases. 
A)  pancreatic proteases are zymogens. 
B)  the pH in the small intestine is unfavorable for activity of pancreatic proteases. 
C)  pancreatic proteases are endopeptidases. 
D)  bacteria destroy pancreatic proteases in the small intestine. 
E)  pepsin from the stomach is required to activate pancreatic proteases. C

Question 2

Absorption of all the major nutrients (fat, protein, polysaccharide) from the gut has which of the following characteristics?

Accepted Answer

A)  Active transport is required. 
B)  ATP hydrolysis, when employed, results in heat production, not useful work. 
C)  The products absorbed are typically derived by hydrolysis of larger molecules. 
D)  Absorption results exclusively in entry into the portal circulation. 
E)  In each case where ATP is employed, the absorbed substance is phosphorylated. 
A)  Active transport is required. 
B)  ATP hydrolysis, when employed, results in heat production, not useful work. 
C)  The products absorbed are typically derived by hydrolysis of larger molecules. 
D)  Absorption results exclusively in entry into the portal circulation. 
E)  In each case where ATP is employed, the absorbed substance is phosphorylated. C

Question 3

Dietary triacylglycerols are mainly hydrolyzed in the intestinal tract by

Accepted Answer

A)  hepatic lipase to glycerol and fatty acids. 
B)  hormone-sensitive lipase to glycerol and fatty acids. 
C)  hormone-sensitive lipase to monoacylglycerol and fatty acids. 
D)  pancreatic lipase to diacylglycerol and fatty acids. 
E)  pancreatic lipase to monoacylglycerol and fatty acids. 
A)  hepatic lipase to glycerol and fatty acids. 
B)  hormone-sensitive lipase to glycerol and fatty acids. 
C)  hormone-sensitive lipase to monoacylglycerol and fatty acids. 
D)  pancreatic lipase to diacylglycerol and fatty acids. 
E)  pancreatic lipase to monoacylglycerol and fatty acids. E

Question 4

What type of cells have secretagogue receptors?

Accepted Answer

A)  Autocrine 
B)  Endocrine 
C)  Exocrine 
D)  Juxtacrine 
E)  Paracrine 
A)  Autocrine 
B)  Endocrine 
C)  Exocrine 
D)  Juxtacrine 
E)  Paracrine

Question 5

Which of the following compounds would you suggest be eliminated from the diet of a patient suffering from galactosemia?

Accepted Answer

A)  leucine 
B)  starch 
C)  lactose 
D)  glucose 
E)  none of the above 
A)  leucine 
B)  starch 
C)  lactose 
D)  glucose 
E)  none of the above

Question 6

What do cardiac glycosides inhibit?

Accepted Answer

A)  Cl-/HCO3- transporter 
B)  Electrogenic Na+ flux 
C)  Na+/H+ transporter 
D)  Na+/K+/2Cl- cotransporter 
E)  Na+/K+-exchanging ATPase 
A)  Cl-/HCO3- transporter 
B)  Electrogenic Na+ flux 
C)  Na+/H+ transporter 
D)  Na+/K+/2Cl- cotransporter 
E)  Na+/K+-exchanging ATPase

Question 7

Primary bile acids are

Accepted Answer

A)  any bile acids found in the small intestine. 
B)  any bile acids reabsorbed from the small intestine. 
C)  synthesized in the small intestine by bacteria. 
D)  synthesized in the liver from cholesterol. 
E)  converted to secondary bile acids by conjugation with glycine or taurine. 
A)  any bile acids found in the small intestine. 
B)  any bile acids reabsorbed from the small intestine. 
C)  synthesized in the small intestine by bacteria. 
D)  synthesized in the liver from cholesterol. 
E)  converted to secondary bile acids by conjugation with glycine or taurine.

Question 8

The processes involved in the secretion of enzymes and electrolytes in the digestion system are regulated and coordinated by which of the following substances?

Accepted Answer

A)  acetyl choline 
B)  histamine 
C)  serotonin 
D)  gastrin 
E)  all of the above 
A)  acetyl choline 
B)  histamine 
C)  serotonin 
D)  gastrin 
E)  all of the above

Question 9

An enzyme present in saliva which hydrolyzes starch to produce free maltose is

Accepted Answer

A)  sucrase. 
B)  alpha-amylase. 
C)  phosphorylase. 
D)  debranching enzyme. 
E)  limit dextrin. 
A)  sucrase. 
B)  alpha-amylase. 
C)  phosphorylase. 
D)  debranching enzyme. 
E)  limit dextrin.

Question 10

All of the following occur at or in the brush border (microvilli) of intestinal mucosal cells EXCEPT which one?

Accepted Answer

A)  Na+-driven cotransport of amino acids. 
B)  Na+-driven cotransport of fatty acids. 
C)  Na+-driven cotransport of glucose. 
D)  conversion of dipeptides to amino acids. 
E)  uptake of monoglycerides. 
A)  Na+-driven cotransport of amino acids. 
B)  Na+-driven cotransport of fatty acids. 
C)  Na+-driven cotransport of glucose. 
D)  conversion of dipeptides to amino acids. 
E)  uptake of monoglycerides.

Question 11

The major site of digestion of dietary fats is the

Accepted Answer

A)  stomach. 
B)  liver. 
C)  small intestine. 
D)  duodenum. 
E)  large bowel. 
A)  stomach. 
B)  liver. 
C)  small intestine. 
D)  duodenum. 
E)  large bowel.

Question 12

Which of the following is the main carrier for the transport of digested fat?

Accepted Answer

A)  chylomicron 
B)  VLDL 
C)  LDL 
D)  HDL 
E)  albumin 
A)  chylomicron 
B)  VLDL 
C)  LDL 
D)  HDL 
E)  albumin

Question 13

Digestive enzymes operating within the gastrointestinal tract may be contributed by each of the following EXCEPT

Accepted Answer

A)  synthesis in the liver. 
B)  synthesis in the gastric mucosa. 
C)  synthesis in the pancreas. 
D)  synthesis in the intestinal mucosa. 
E)  bacterial flora. 
A)  synthesis in the liver. 
B)  synthesis in the gastric mucosa. 
C)  synthesis in the pancreas. 
D)  synthesis in the intestinal mucosa. 
E)  bacterial flora.

Question 14

The complete digestion by humans of starch or glycogen to glucose requires

Accepted Answer

A)  only amylase. 
B)  only phosphorylase. 
C)  amylase, an oligo-alpha-1,6-glycosidase, and a maltase. 
D)  amylase and sucrase. 
E)  a poly-alpha-1,4-glucosidase. 
A)  only amylase. 
B)  only phosphorylase. 
C)  amylase, an oligo-alpha-1,6-glycosidase, and a maltase. 
D)  amylase and sucrase. 
E)  a poly-alpha-1,4-glucosidase.

Question 15

Which statement about protein digestion in the stomach and intestines is FALSE?

Accepted Answer

A)  Trypsin can activate all zymogens of pancreatic proteases. 
B)  pepsin is irreversibly inactivated when the pH is above 5. 
C)  Chymotrypsin and trypsin show similar specificity in catalyzing the hydrolysis of peptide bonds. 
D)  The action of pepsin in the stomach produces primarily peptide fragments of proteins. 
E)  Intestinal peptidases are required to digest di- and tri-peptides. 
A)  Trypsin can activate all zymogens of pancreatic proteases. 
B)  pepsin is irreversibly inactivated when the pH is above 5. 
C)  Chymotrypsin and trypsin show similar specificity in catalyzing the hydrolysis of peptide bonds. 
D)  The action of pepsin in the stomach produces primarily peptide fragments of proteins. 
E)  Intestinal peptidases are required to digest di- and tri-peptides.

Question 16

Cellulose is not digested by humans because it

Accepted Answer

A)  is a relatively insoluble protein-carbohydrate complex inaccessible to digestive enzymes. 
B)  is a mucopolysaccharide, which is not a substrate for digestive enzymes. 
C)  is highly sulfated, making it inaccessible to the action of most glycosidases. 
D)  is a polymer of glucose molecules in beta 1-4 linkage for which we have no digestive enzymes. 
E)  resists enzyme action due to its highly branched structure. 
A)  is a relatively insoluble protein-carbohydrate complex inaccessible to digestive enzymes. 
B)  is a mucopolysaccharide, which is not a substrate for digestive enzymes. 
C)  is highly sulfated, making it inaccessible to the action of most glycosidases. 
D)  is a polymer of glucose molecules in beta 1-4 linkage for which we have no digestive enzymes. 
E)  resists enzyme action due to its highly branched structure.

Question 17

Which is classified as an exopeptidase?

Accepted Answer

A)  trypsin 
B)  chymotrypsinogen 
C)  carboxypeptidase 
D)  enterokinase 
E)  pepsin 
A)  trypsin 
B)  chymotrypsinogen 
C)  carboxypeptidase 
D)  enterokinase 
E)  pepsin

Question 18

Which transport mechanism is unique to parietal cells for the transport of HCl?

Accepted Answer

A)  Cl-/HCO3- exchanger 
B)  Cl-/Na+ antiporter 
C)  Electrogenic Cl- flux 
D)  K+/H+ -exchanging ATPase 
E)  Na+/H+ transporter 
A)  Cl-/HCO3- exchanger 
B)  Cl-/Na+ antiporter 
C)  Electrogenic Cl- flux 
D)  K+/H+ -exchanging ATPase 
E)  Na+/H+ transporter

Question 19

The action of pancreatic amylase followed by maltase on starch would yield

Accepted Answer

A)  fructose, isomaltose and glucose. 
B)  maltose, alpha-dextrins and lactose. 
C)  amylose and alpha-dextrins. 
D)  maltotriose, glucose and alpha-dextrins. 
E)  maltose, maltotriose and amylose. 
A)  fructose, isomaltose and glucose. 
B)  maltose, alpha-dextrins and lactose. 
C)  amylose and alpha-dextrins. 
D)  maltotriose, glucose and alpha-dextrins. 
E)  maltose, maltotriose and amylose.

Question 20

Chylomicrons are

Accepted Answer

A)  produced in the gut, and contain triglycerides, cholesterol, cholesteryl esters, protein, phospholipids. 
B)  produced in the liver and contain triglycerides, cholesterol, cholesteryl esters, protein, phospholipids. 
C)  produced in the intestine and the liver and contain largely cholesterol and phospholipids. 
D)  produced in the intestine and contain bile salts in addition to triglycerides, cholesterol and phospholipids. 
E)  the smallest of the serum lipoprotein particles. 
A)  produced in the gut, and contain triglycerides, cholesterol, cholesteryl esters, protein, phospholipids. 
B)  produced in the liver and contain triglycerides, cholesterol, cholesteryl esters, protein, phospholipids. 
C)  produced in the intestine and the liver and contain largely cholesterol and phospholipids. 
D)  produced in the intestine and contain bile salts in addition to triglycerides, cholesterol and phospholipids. 
E)  the smallest of the serum lipoprotein particles.

Exam 25: Digestion and Absorption of Basic Nutritional Constituents

Pancreatic enzymes cannot catalyze the complete digestion of dietary proteins to amino acids in the intestine because

Absorption of all the major nutrients (fat, protein, polysaccharide) from the gut has which of the following characteristics?

Dietary triacylglycerols are mainly hydrolyzed in the intestinal tract by

What type of cells have secretagogue receptors?

Which of the following compounds would you suggest be eliminated from the diet of a patient suffering from galactosemia?

What do cardiac glycosides inhibit?

Primary bile acids are

The processes involved in the secretion of enzymes and electrolytes in the digestion system are regulated and coordinated by which of the following substances?

An enzyme present in saliva which hydrolyzes starch to produce free maltose is

All of the following occur at or in the brush border (microvilli) of intestinal mucosal cells EXCEPT which one?

The major site of digestion of dietary fats is the

Which of the following is the main carrier for the transport of digested fat?

Digestive enzymes operating within the gastrointestinal tract may be contributed by each of the following EXCEPT

The complete digestion by humans of starch or glycogen to glucose requires

Which statement about protein digestion in the stomach and intestines is FALSE?

Cellulose is not digested by humans because it

Which is classified as an exopeptidase?

Which transport mechanism is unique to parietal cells for the transport of HCl?

The action of pancreatic amylase followed by maltase on starch would yield

Chylomicrons are

Eukaryotic Cell Structure

DNA and RNA: Composition and Structure

Protein I: Composition and Structure

DNA Replication, Recombination, and Repair

RNA: Transcription and Rna Processing

Protein Synthesis: Translation and Posttranslational Modifications

Recombinant Dna and Biotechnology

Regulation of Gene Expression

Protein II: Structure-Function Relationships in Protein Families

Enzymes: Classification, Kinetics, and Control

The Cytochromes P450 and Nitric Oxide Synthases

Biological Membranes: Structure and Membrane Transport

Fundamentals of Signal Transduction

Bioenergetics and Oxidative Metabolism

Carbohydrate Metabolism I: Major Metabolic Pathways and Their Control

Carbohydrate Metabolism II: Special Pathways and Glycoconjugates

Lipid Metabolism I: Synthesis, Storage, and Utilization of Fatty Acids and Triacylglycerols

Lipid Metabolism II: Pathways of Metabolism of Special Lipids

Amino Acid Metabolism

Purine and Pyrimidine Nucleotide Metabolism

Metabolic Interrelationships

Biochemistry of Hormones

Molecular Cell Biology

Cell Cycle, Programmed Cell Death, and Cancer

Digestion and Absorption of Basic Nutritional Constituents

Principles of Nutrition I and II

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