Question 1

Zymogens of gastric and pancreatic proteases are activated by

Accepted Answer

A)  aggregation of monomers. 
B)  glycosylation. 
C)  formation of covalent crosslinks. 
D)  proteolysis. 
E)  association with coenzymes. 
A)  aggregation of monomers. 
B)  glycosylation. 
C)  formation of covalent crosslinks. 
D)  proteolysis. 
E)  association with coenzymes.

Question 2

All of the following statements about alpha-amylase are correct EXCEPT which one?

Accepted Answer

A)  Small branched dextrins are poor substrates for the enzyme. 
B)  Amylopectin and glycogen are normal substrates. 
C)  The major product of its action on amylose is glucose. 
D)  The enzyme catalyzes the hydrolysis of alpha-1,4-glucosidic linkages. 
E)  For humans, the most important occurrence of the enzyme is in the secretion of the pancreas. 
A)  Small branched dextrins are poor substrates for the enzyme. 
B)  Amylopectin and glycogen are normal substrates. 
C)  The major product of its action on amylose is glucose. 
D)  The enzyme catalyzes the hydrolysis of alpha-1,4-glucosidic linkages. 
E)  For humans, the most important occurrence of the enzyme is in the secretion of the pancreas.

Question 3

Which enzyme is an endopeptidase secreted as a zymogen by the pancreas?

Accepted Answer

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

Question 4

How is iron transfer across the mucosal-capillary interface regulated?

Accepted Answer

A)  Change in the number of mucosal cells 
B)  Changes in pH 
C)  Degradation of heme-associated iron 
D)  Synthesis of apoferritin 
E)  Synthesis of transferrin 
A)  Change in the number of mucosal cells 
B)  Changes in pH 
C)  Degradation of heme-associated iron 
D)  Synthesis of apoferritin 
E)  Synthesis of transferrin

Question 5

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.

Question 6

Which enzyme of intestinal origin activates trypsinogen?

Accepted Answer

A)  pepsin 
B)  carboxypeptidase 
C)  chymotrypsin 
D)  enterokinase 
E)  cholecystokinin 
A)  pepsin 
B)  carboxypeptidase 
C)  chymotrypsin 
D)  enterokinase 
E)  cholecystokinin

Question 7

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 8

The excretion of iron

Accepted Answer

A)  is regulated by the rate of iron absorption. 
B)  occurs mainly as a result of desquamation of cells. 
C)  involves transfer of iron from transferrin to renal tubular cells. 
D)  is the process by which total body iron is regulated. 
A)  is regulated by the rate of iron absorption. 
B)  occurs mainly as a result of desquamation of cells. 
C)  involves transfer of iron from transferrin to renal tubular cells. 
D)  is the process by which total body iron is regulated.

Question 9

Normal cellular uptake of iron from the blood occurs by the process of

Accepted Answer

A)  ATP-dependent active transport. 
B)  erythrocytosis. 
C)  hemochromatosis. 
D)  passive diffusion. 
E)  receptor-mediated endocytosis. 
A)  ATP-dependent active transport. 
B)  erythrocytosis. 
C)  hemochromatosis. 
D)  passive diffusion. 
E)  receptor-mediated endocytosis.

Question 10

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 11

The primary function of ferritin is best described as

Accepted Answer

A)  providing storage of iron within cells. 
B)  providing storage of iron within the intestinal lumen. 
C)  providing storage of iron within the renal tubules. 
D)  providing transport of iron through the plasma. 
A)  providing storage of iron within cells. 
B)  providing storage of iron within the intestinal lumen. 
C)  providing storage of iron within the renal tubules. 
D)  providing transport of iron through the plasma.

Question 12

Monoglycerides formed by digestion of unmodified animal fats usually contain

Accepted Answer

A)  a saturated fatty acid residue. 
B)  an unsaturated fatty acid residue. 
C)  about equal amounts of saturated and unsaturated fatty acid residues. 
A)  a saturated fatty acid residue. 
B)  an unsaturated fatty acid residue. 
C)  about equal amounts of saturated and unsaturated fatty acid residues.

Question 13

Chymotrypsin is

Accepted Answer

A)  an enterokinase. 
B)  an endopeptidase. 
C)  a carboxypeptidase. 
D)  the precursor of trypsin. 
E)  an aminopeptidase. 
A)  an enterokinase. 
B)  an endopeptidase. 
C)  a carboxypeptidase. 
D)  the precursor of trypsin. 
E)  an aminopeptidase.

Question 14

Iron regulatory proteins (IRPs) participate in cellular iron homeostasis through direct interactions with

Accepted Answer

A)  Clathrin-coated pits 
B)  DNA-histone complexes 
C)  mRNA molecules 
D)  membrane transport systems 
E)  transcription factors 
A)  Clathrin-coated pits 
B)  DNA-histone complexes 
C)  mRNA molecules 
D)  membrane transport systems 
E)  transcription factors

Question 15

All of the following would be able to function as emulsifying agents in water EXCEPT which one?

Accepted Answer

A)  sphingomyelin 
B)  2-acylglycerol 
C)  phosphatidylcholine 
D)  sodium stearate 
E)  cholesterol ester 
A)  sphingomyelin 
B)  2-acylglycerol 
C)  phosphatidylcholine 
D)  sodium stearate 
E)  cholesterol ester

Question 16

Lactase catalyzes which of the following?

Accepted Answer

A)  galactose --> glucose + glucose 6-phosphate 
B)  sucrose --> glucose + fructose 
C)  lactate --> glucose + galactose 
D)  lactose --> glucose + galactose 
E)  lactate --> pyruvate 
A)  galactose --> glucose + glucose 6-phosphate 
B)  sucrose --> glucose + fructose 
C)  lactate --> glucose + galactose 
D)  lactose --> glucose + galactose 
E)  lactate --> pyruvate

Question 17

Iron uptake in the intestine is promoted by all of the following except:

Accepted Answer

A)  a low pH. 
B)  a high pH. 
C)  ascorbic acid (vitamin 
C)  to maintain iron in the ferrous form. 
D)  a diet rich in heme. 
A)  a low pH. 
B)  a high pH. 
C)  ascorbic acid (vitamin 
C)  to maintain iron in the ferrous form. 
D)  a diet rich in heme.

Question 18

The major site of carbohydrate digestion is the

Accepted Answer

A)  mouth. 
B)  stomach. 
C)  small intestine. 
D)  large intestine. 
E)  pancreas. 
A)  mouth. 
B)  stomach. 
C)  small intestine. 
D)  large intestine. 
E)  pancreas.

Question 19

Hemochromatosis is:

Accepted Answer

A)  Treated with blood transfusions 
B)  An acquired anemia 
C)  Treated with a high carbohydrate diet 
D)  A consequence of hemorrhagic disease 
E)  Accompanied by saturated transferrin 
A)  Treated with blood transfusions 
B)  An acquired anemia 
C)  Treated with a high carbohydrate diet 
D)  A consequence of hemorrhagic disease 
E)  Accompanied by saturated transferrin

Question 20

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.

Exam 26: Digestion and Absorption of Basic Nutritional Constituents

Zymogens of gastric and pancreatic proteases are activated by

All of the following statements about alpha-amylase are correct EXCEPT which one?

Which enzyme is an endopeptidase secreted as a zymogen by the pancreas?

How is iron transfer across the mucosal-capillary interface regulated?

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

Which enzyme of intestinal origin activates trypsinogen?

The major site of digestion of dietary fats is the

The excretion of iron

Normal cellular uptake of iron from the blood occurs by the process of

Primary bile acids are

The primary function of ferritin is best described as

Monoglycerides formed by digestion of unmodified animal fats usually contain

Chymotrypsin is

Iron regulatory proteins (IRPs) participate in cellular iron homeostasis through direct interactions with

All of the following would be able to function as emulsifying agents in water EXCEPT which one?

Lactase catalyzes which of the following?

Iron uptake in the intestine is promoted by all of the following except:

The major site of carbohydrate digestion is the

Hemochromatosis is:

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

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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