Question 1

Which of the following statements is correct?

Accepted Answer

A)  iron absorption into mucosal cells of the gut is a simple diffusion process. 
B)  Hemosiderin is produced by denaturation of ferritin with the loss of some apoprotein. 
C)  Apotransferrin is a large protein complex capable of binding thousands of iron hydroxide molecules. 
D)  iron is transported in blood chiefly as part of ferritin. 
E)  oxidizing agents promote the absorption of iron from the intestine. 
A)  iron absorption into mucosal cells of the gut is a simple diffusion process. 
B)  Hemosiderin is produced by denaturation of ferritin with the loss of some apoprotein. 
C)  Apotransferrin is a large protein complex capable of binding thousands of iron hydroxide molecules. 
D)  iron is transported in blood chiefly as part of ferritin. 
E)  oxidizing agents promote the absorption of iron from the intestine.

Question 2

Lactose intolerance is caused by deficient activity of

Accepted Answer

A)  galactose 1-phosphate uridylyltransferase. 
B)  amylase. 
C)  lactose dehydrogenase. 
D)  lactase. 
E)  galactokinase. 
A)  galactose 1-phosphate uridylyltransferase. 
B)  amylase. 
C)  lactose dehydrogenase. 
D)  lactase. 
E)  galactokinase.

Question 3

In the transport of glucose from the intestinal lumen through the epithelial cells, which of the following is NOT true?

Accepted Answer

A)  A metabolic poison (cyanide) or absence of oxygen would have no effect. 
B)  It requires sodium, potassium ATPase. 
C)  It is unidirectional. 
D)  It is stereospecific. 
E)  Cotransport with sodium occurs. 
A)  A metabolic poison (cyanide) or absence of oxygen would have no effect. 
B)  It requires sodium, potassium ATPase. 
C)  It is unidirectional. 
D)  It is stereospecific. 
E)  Cotransport with sodium occurs.

Question 4

All of the following are part of the process of protein digestion EXCEPT

Accepted Answer

A)  denaturation of many proteins at the pH of gastric juice. 
B)  the action of enteropeptidase (enterokinase) on pro-aminopeptidase. 
C)  conversion of pepsinogen to pepsin by the action of pepsinogen. 
D)  catalysis of protein hydrolysis by both endo- and exopeptidases. 
E)  the action of specific dipeptidases. 
A)  denaturation of many proteins at the pH of gastric juice. 
B)  the action of enteropeptidase (enterokinase) on pro-aminopeptidase. 
C)  conversion of pepsinogen to pepsin by the action of pepsinogen. 
D)  catalysis of protein hydrolysis by both endo- and exopeptidases. 
E)  the action of specific dipeptidases.

Question 5

All of the following statements are correct EXCEPT which one?

Accepted Answer

A)  triglyceride digestion requires a lipase produced by the pancreas. 
B)  triglycerides can be emulsified in the gut using bile salts. 
C)  Phospholipids can aid emulsification of triglycerides in the gut. 
D)  lipases use water as a cosubstrate. 
E)  Long chain acyl-CoA's are products when lipases degrade triglycerides. 
A)  triglyceride digestion requires a lipase produced by the pancreas. 
B)  triglycerides can be emulsified in the gut using bile salts. 
C)  Phospholipids can aid emulsification of triglycerides in the gut. 
D)  lipases use water as a cosubstrate. 
E)  Long chain acyl-CoA's are products when lipases degrade triglycerides.

Question 6

Pancreatic lipase is an enzyme which

Accepted Answer

A)  hydrolyzes triglycerides to glycerol plus fatty acid. 
B)  specifically attacks the 2-position of triglycerides. 
C)  specifically attacks the 1- and 3-ester linkages of triglycerides. 
D)  specifically hydrolyzes 2-monoglycerides to glycerol and fatty acid. 
E)  specifically hydrolyzes phospholipids. 
A)  hydrolyzes triglycerides to glycerol plus fatty acid. 
B)  specifically attacks the 2-position of triglycerides. 
C)  specifically attacks the 1- and 3-ester linkages of triglycerides. 
D)  specifically hydrolyzes 2-monoglycerides to glycerol and fatty acid. 
E)  specifically hydrolyzes phospholipids.

Question 7

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 8

All of the following EXCEPT which are true about ferritin?

Accepted Answer

A)  Ferritin synthesis is proportional to the iron load in a cell. 
B)  Ferritin acts to store iron within cells. 
C)  Ferritin is essential for the intercellular (cell to cell) transport of iron. 
D)  Ferritin can store up to 4500 atoms of iron per molecule of ferritin. 
A)  Ferritin synthesis is proportional to the iron load in a cell. 
B)  Ferritin acts to store iron within cells. 
C)  Ferritin is essential for the intercellular (cell to cell) transport of iron. 
D)  Ferritin can store up to 4500 atoms of iron per molecule of ferritin.

Question 9

Which of the following statements about transferrin is correct?

Accepted Answer

A)  It binds ferric ion. 
B)  It has four binding sites. 
C)  The binding sites demonstrate cooperativity. 
D)  It is an example of gene quadruplication. 
E)  None of the above. 
A)  It binds ferric ion. 
B)  It has four binding sites. 
C)  The binding sites demonstrate cooperativity. 
D)  It is an example of gene quadruplication. 
E)  None of the above.

Question 10

Which of the following statements is correct?

Accepted Answer

A)  iron absorption from the gut occurs at a rate which is independent of the quantity of body iron stores 
B)  ferritin is responsible for storage of most of the body iron 
C)  transferrin is a large spherical cluster of protein molecules capable of binding thousands of iron hydroxide molecules 
D)  iron is transported in blood chiefly as hemosiderin 
E)  iron is transported as both Fe+2 and Fe+3 
A)  iron absorption from the gut occurs at a rate which is independent of the quantity of body iron stores 
B)  ferritin is responsible for storage of most of the body iron 
C)  transferrin is a large spherical cluster of protein molecules capable of binding thousands of iron hydroxide molecules 
D)  iron is transported in blood chiefly as hemosiderin 
E)  iron is transported as both Fe+2 and Fe+3

Question 11

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 12

Which type of reaction BEST characterizes the process of digestion?

Accepted Answer

A)  hydrolysis 
B)  dehydration 
C)  dehydrogenation 
D)  phosphorolysis 
E)  hydrogenation 
A)  hydrolysis 
B)  dehydration 
C)  dehydrogenation 
D)  phosphorolysis 
E)  hydrogenation

Question 13

Which enzyme is responsible for the conversion of pepsinogen to pepsin?

Accepted Answer

A)  enteropeptidase 
B)  gastrin 
C)  pepsin 
D)  trypsin 
E)  Both B and C are correct. 
A)  enteropeptidase 
B)  gastrin 
C)  pepsin 
D)  trypsin 
E)  Both B and C are correct.

Question 14

Concerning the bile acids, which of the following statements is/are CORRECT

Accepted Answer

A)  glycocholic and taurocholic acids are the major conjugated bile acids. 
B)  some of the conjugated bile acids are returned to the liver from the intestine via the enterohepatic circulation. 
C)  the major lipid components of bile, besides the conjugated bile acids, are phosphatidyl choline and cholesterol. 
D)  all of the above. 
E)  none of the above. 
A)  glycocholic and taurocholic acids are the major conjugated bile acids. 
B)  some of the conjugated bile acids are returned to the liver from the intestine via the enterohepatic circulation. 
C)  the major lipid components of bile, besides the conjugated bile acids, are phosphatidyl choline and cholesterol. 
D)  all of the above. 
E)  none of the above.

Question 15

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 16

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 17

All of the following are true of mixed micelles formed in the intestine EXCEPT which one?

Accepted Answer

A)  They provide a vehicle for the absorption of fat soluble vitamins. 
B)  They are absorbed directly into the lymphatic system via the lacteals. 
C)  Cholesterol is often a component of micelles. 
D)  Micelles contain mainly free fatty acids and monoacylglycerols. 
E)  The non-polar ends of lipids are oriented toward the center of the micelles. 
A)  They provide a vehicle for the absorption of fat soluble vitamins. 
B)  They are absorbed directly into the lymphatic system via the lacteals. 
C)  Cholesterol is often a component of micelles. 
D)  Micelles contain mainly free fatty acids and monoacylglycerols. 
E)  The non-polar ends of lipids are oriented toward the center of the micelles.

Question 18

What are the total products of triglyceride digestion in the lumen of the small intestines?

Accepted Answer

A)  Free glycerol and free fatty acids. 
B)  2-Monoglycerides and free fatty acids. 
C)  1-Monoglycerides and free fatty acids 
D)  2-Monoglycerides, free glycerol and free fatty acids. 
E)  Diglycerides and free fatty acids. 
A)  Free glycerol and free fatty acids. 
B)  2-Monoglycerides and free fatty acids. 
C)  1-Monoglycerides and free fatty acids 
D)  2-Monoglycerides, free glycerol and free fatty acids. 
E)  Diglycerides and free fatty acids.

Question 19

Which of the following statements is true concerning secretagogues?

Accepted Answer

A)  They are secreted by exocrine glands into the digestive tract 
B)  They stimulate the secretion of calcium ions into the digestive tract 
C)  They may be comprised of neurotransmitters and hormones that act on exocrine cells 
D)  They are cleaved by digestive enzymes and absorbed into small intestine 
E)  They are released as zymogens from exocrine cells 
A)  They are secreted by exocrine glands into the digestive tract 
B)  They stimulate the secretion of calcium ions into the digestive tract 
C)  They may be comprised of neurotransmitters and hormones that act on exocrine cells 
D)  They are cleaved by digestive enzymes and absorbed into small intestine 
E)  They are released as zymogens from exocrine cells

Question 20

Which of the following is involved in the conversion of a zymogen into an active enzyme in the intestine?

Accepted Answer

A)  carboxypeptidase 
B)  cholecystokinin 
C)  pepsin 
D)  enterokinase 
E)  all of the above 
A)  carboxypeptidase 
B)  cholecystokinin 
C)  pepsin 
D)  enterokinase 
E)  all of the above

Exam 26: Digestion and Absorption of Basic Nutritional Constituents

Which of the following statements is correct?

Lactose intolerance is caused by deficient activity of

In the transport of glucose from the intestinal lumen through the epithelial cells, which of the following is NOT true?

All of the following are part of the process of protein digestion EXCEPT

All of the following statements are correct EXCEPT which one?

Pancreatic lipase is an enzyme which

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

All of the following EXCEPT which are true about ferritin?

Which of the following statements about transferrin is correct?

Which of the following statements is correct?

Which is classified as an exopeptidase?

Which type of reaction BEST characterizes the process of digestion?

Which enzyme is responsible for the conversion of pepsinogen to pepsin?

Concerning the bile acids, which of the following statements is/are CORRECT

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

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

All of the following are true of mixed micelles formed in the intestine EXCEPT which one?

What are the total products of triglyceride digestion in the lumen of the small intestines?

Which of the following statements is true concerning secretagogues?

Which of the following is involved in the conversion of a zymogen into an active enzyme in the intestine?

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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