CHAPTER 23
Biochemical Energy Production
Test Bank
TYPE I MULTIPLE-CHOICE QUESTIONS
In each of the following multiple-choice questions, place the letter of the correct response in the blank
at the left. There is only one correct response for each question.
23.1
a
[Algorithmic]Which of the following statements about metabolism is correct?
a) Catabolism includes all metabolic reactions in which large molecules are broken
down into smaller ones.
b) Catabolic reaction sequences usually consume energy.
c) Anabolism is the sum total of all chemical reactions that take place within a cell.
d) The process of digestion is an anabolic process.
23.2
d
[Algorithmic]Which of the following statements about mitochondria is correct?
a) Mitochondria contain a multi-folded outer membrane and an unfolded inner
membrane.
b) The space between the inner and outer mitochondrial membrane is called the
matrix.
c) The inner mitochondrial membrane separates the matrix and the ATP-synthase
regions.
d) Mitochondria are located within the cellular cytosol.
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259
260
Chapter 23: Biochemical Energy Production
23.3
c
23.4
c
Test Bank
Which of the following diagrams gives the correct identities and arrangement of the
structural subunits in coenzyme A?
a)
pantothenic acid
2-aminoethanethiol
phosphorylated ATP
b)
pantothenic acid
2-aminoethanethiol
ADP
c)
2-aminoethanethiol
pantothenic acid
phosphorylated ATP
d)
2-aminoethanethiol
pantothenic acid
ADP
The missing structural subunit in the following diagram for flavin adenine
dinucleotide is
flavin
adenine
a)
b)
c)
d)
?
phosphate
ribose
phosphate
phosphate.
ribose.
ribitol.
deoxyribose.
23.5
c
The correct notation for the reduced form of nicotinamide adenine dinucleotide is
a) NAD+.
b) NAD.
c) NADH.
d) NADH2.
23.6
c
Which of the following is a correct skeletal equation for a hydrolysis reaction
involving adenosine phosphates?
a) ATP  ADP + 2Pi
b) ADP  AMP + 2Pi
c) ATP  AMP + PPi
d) ATP  ADP + PPi
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Test Bank
Chapter 23: Biochemical Energy Production
261
23.7
a
The “active” portion of coenzyme A is the
a) sulfhydryl group of 2-aminoethanethiol.
b) B vitamin pantothenic acid.
c) phosphate group on carbon 3' of ribose.
d) amino group of 2-aminoethanethiol.
23.8
a
The “fuel” for the citric acid cycle is
a) acetyl CoA.
b) citric acid.
c) citrate ion.
d) oxaloacetate ion.
23.9
a
Which of the following is a correct general description of the reaction that occurs in
the first step of the citric acid cycle?
a) C2 + C4  C6
b) C3 + C3  C6
c) C2 + C2 + C2  C6
d) C4 + C4  C6 + C2
23.10
c
In which two steps of the citric acid cycle are molecules of carbon dioxide produced?
a) steps 2 and 5
b) steps 3 and 5
c) steps 3 and 4
d) steps 4 and 6
23.11
b
How many NADH and FADH2 molecules are produced, respectively, during one turn
of the citric acid cycle?
a) 2, 2
b) 3, 1
c) 1, 3
d) 2, 3
23.12
c
[Algorithmic]Which of the following citric acid intermediates is not a C4 species?
a) oxaloacetate
b) succinate
c) -ketoglutarate
d) malate
23.13
b
[Algorithmic]In which of the following listings of citric acid cycle intermediates are
the compounds listed in the order in which they are encountered in a turn of the
cycle?
a) isocitrate, oxaloacetate, succinate
b) succinate, malate, oxaloacetate
c) fumarate, oxaloacetate, malate
d) malate, fumarate, oxaloacetate
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Chapter 23: Biochemical Energy Production
23.14
d
At which step in the electron transport chain does O2 participate?
a) first step
b) second step
c) next to last step
d) last step
23.15
c
The number of membrane-bound protein complexes associated with the electron
transport chain is
a) one.
b) two.
c) three.
d) four.
23.16
b
Which of the following electron carriers is not part of a membrane-bound protein
complex in the electron transport chain?
a) FeSP
b) CoQ
c) cyt c1
d) cyt a3
23.17
b
Which of the following sets of electron carriers is associated with the electron
transport chain reactions that occur at protein complex I?
a) CoQ, FeSP, cyt b, cyt c
b) NADH, FMN, FeSP, CoQ
c) cyt c, cyt a, cyt a3
d) FADH2, FeSP, CoQ
23.18
c
ATP synthesis via oxidative phosphorylation depends on the passage of which of the
following species through membrane-bound ATP synthase?
a) NADH
b) FADH2
c) H+
d) NAD+
23.19
b
[Algorithmic]How many moles of ATP result from the entry of one mole of FADH 2
into the electron transport chain?
a) 1
b) 1.5
c) 2
d) 2.5
23.20
c
[Algorithmic]How many ATP molecules result from the “processing” of one acetyl
CoA molecule through the common metabolic pathway?
a) 2
b) 8
c) 10
d) 24
Test Bank
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Test Bank
Chapter 23: Biochemical Energy Production
263
TYPE II MULTIPLE-CHOICE QUESTIONS
In each of the following multiple-choice questions, place the letter of the correct response in the blank
at the left. There may be more than one correct response (choice d) or no correct response for a
question (choice e).
23.21
a
In a mitochondrion the
a) inner membrane separates the matrix from the intermembrane space.
b) the inner membrane is more permeable than the outer membrane.
c) ATP-synthase complexes are found on the folds of the outer membrane.
d) more than one correct response
e) no correct response
23.22
e
Which of the following substances does not contain a B vitamin as a structural
subunit?
a) flavin adenine dinucleotide
b) nicotinamide adenine dinucleotide
c) coenzyme A
d) more than one correct response
e) no correct response
23.23
b
Which of the following substances has two unsubstituted ribose molecules as
structural subunits?
a) FADH2
b) NAD+
c) CoA
d) more than one correct response
e) no correct response
23.24
a
Which of the following substances contains two or more high energy phosphate
bonds?
a) ATP
b) ADP
c) AMP
d) more than one correct response
e) no correct response
23.25
b
Which of the following is a correct letter designation for the reduced form of a
coenzyme?
a) NAD+
b) FADH2
c) NADH2
d) more than one correct response
e) no correct response
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264
Chapter 23: Biochemical Energy Production
23.26
e
Which of the following are products of the citric acid cycle?
a) acetyl CoA and NAD+
b) acetyl CoA and CO2
c) CO2 and H2O
d) more than one correct response
e) no correct response
23.27
b
Which of the following citric acid cycle intermediates is decarboxylated during the
operation of the cycle?
a) oxaloacetate
b) isocitrate
c) succinate
d) more than one correct response
e) no correct response
23.28
d
Which of the following citric acid cycle intermediates is a C4 species?
a) fumarate
b) citrate
c) malate
d) more than one correct response
e) no correct response
23.29
b
In which of the following citric acid cycle reactions does the coenzyme FAD
participate?
a) citrate  isocitrate
b) succinate  fumarate
c) malate  oxaloacetate
d) more than one correct response
e) no correct response
23.30
d
Which of the following statements concerning citric acid cycle reactions is correct?
a) Two secondary alcohol oxidations occur.
b) Water adds to a carbon-carbon double bond once.
c) Two phosphorylation reactions occur.
d) more than one correct response
e) no correct response
23.31
c
Which of the following carry electrons from the citric acid cycle to the electron
carriers of the electron transport chain?
a) CoA
b) NAD+
c) FADH2
d) more than one correct response
e) no correct response
Test Bank
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Test Bank
Chapter 23: Biochemical Energy Production
265
23.32
e
Which of the following carriers transports electrons from protein complex I to protein
complex III during operation of the electron transport chain?
a) cyt a3
b) cyt c1
c) FMN
d) more than one correct response
e) no correct response
23.33
c
Which of the following substances is both a reactant and a product in the operation of
the electron transport chain?
a) O2
b) FADH2
c) CoQ
d) more than one correct response
e) no correct response
23.34
d
At which protein complex site in the electron transport chain does proton pumping
occur?
a) protein complex I
b) protein complex II
c) protein complex III
d) more than one correct response
e) no correct response
23.35
d
Oxidative phosphorylation is the process in which ATP is synthesized
a) from ATP synthase.
b) from ADP.
c) using energy from the dissipation of a “proton gradient.”
d) more than one correct response
e) no correct response
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266
Chapter 23: Biochemical Energy Production
Test Bank
MULTIPLE-CHOICE FORMAT TRUE-FALSE QUESTIONS
In each of the following multiple-choice questions characterize EACH of the three given statements as
being TRUE or FALSE and then indicate the collective true-false status of the statements using the
choices
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
23.36 c - TFF Statements:
(1) In the last step of the ETC, molecular oxygen is converted to water.
(2) The B vitamin portion of the structure of coenzyme A, which involves
riboflavin, is the reactive site in the molecule.
(3) All of the reactions of the CAC take place in the mitochondrial matrix.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
23.37 d - FFF Statements:
(1) FADH2 is the oxidized form of the coenzyme flavin adenine dinucleotide.
(2) All of the electron carriers of the ETC contain iron, and one of them also
contains copper.
(3) One turn of the CAC generates two CO2 molecules, two NADH molecules and
two FAD2 molecules.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
23.38 a - TTT Statements:
(1) Both ribosomes and mitochondria are examples of organelles.
(2) Cytochromes are heme-containing proteins that can undergo reversible
oxidation and reduction.
(3) The electrons that pass through the various steps of the ETC lose some energy
with each transfer along the chain.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
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Test Bank
23.39 b - TFT
Chapter 23: Biochemical Energy Production
267
Statements:
(1) In the first step of the CAC, a C2 molecule and a C4 molecule combine to
produce a C6 molecule.
(2) ATP, ADP, and AMP differ from each other in the number of adenine
subunits present.
(3) The process by which ATP is produced during the operation of the ETC is
called oxidative phosphorylation.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
23.40 a - TTT Statements:
(1) High-energy phosphate compounds contain one or more strained bonds which
release above-average amounts of energy when broken.
(2) In the ETC, NADH is oxidized to NAD+.
(3) The “fuel” for the CAC is acetyl CoA.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
23.41 c - TFF Statements:
(1) The CO2 molecules produced in the citric acid cycle are the CO2 molecules we
exhale in the process of respiration.
(2) The oxidized form of nicotinamide adenine dinucleotide is NAD+ and the
reduced form in NADH2.
(3) During ETC operation, a buildup of protons occurs on the matrix side of the
inner mitochondrial membrane.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
23.42 c - FTF Statements:
(1) Two ribose subunits are present in the coenzyme flavin adenine dinucleotide.
(2) In the common metabolic pathway, 10 molecules of ATP are produced per
acetyl CoA catabolized.
(3) The purpose of step 2 in the CAC is to convert a secondary alcohol to a
tertiary alcohol.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
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268
Chapter 23: Biochemical Energy Production
Test Bank
23.43 a - TTT Statements:
(1) Some, but not all, protein complex sites associated with the ETC serve as
proton pumps.
(2) The rate at which the CAC operates is controlled by the body’s need for ATP.
(3) Anabolic reactions usually require energy input in order to proceed.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
23.44 b - FTT
Statements:
(1) Mitochondria contain a multifolded outer membrane and an inner membrane.
(2) Two of the electron carriers of the ETC transport change are “mobile,”
moving between protein complex sites.
(3) The NADH and FAD2 formed during the CAC carry electrons and H+ ions to
the ETC.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
23.45 b - TFT
Statements:
(1) Inhibition of the ETC is the mechanism by which cyanide exerts its deadly
effect.
(2) Brown fat cells contain the uncoupling agent thermogenin, a protein that
creates a proton channel through the outer mitochondrial membrane.
(3) One of the body’s mechanisms for adaptation to cold is the production of
brown fat tissue.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
MATCHING QUESTIONS
For each of the molecular structural characteristics on the left, select the correct molecule from the
response list on the right. Responses on the right may be used more than once or need not be used at
all.
23.46
b
Contains a pantothenic acid subunit
23.47
b
Contains a phosphorylated ribose subunit
23.48
a
Does not contain a B vitamin as part of its structure
23.49
b
Reactive site in the molecule is a –SH group
23.50
c
Contains a ribitol subunit
a)
b)
c)
d)
ATP
CoA
FAD
NAD+
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Test Bank
269
Chapter 23: Biochemical Energy Production
For each of the citric acid cycle reactions on the left, select the type of molecules involved (in terms
of number of carbon atoms present) using the response list on the right. Responses on the right may
be used more than once or need not be used at all.
23.51
a
Citrate  isocitrate
23.52
d
Succinate  fumarate
23.53
b
Isocitrate  -ketoglutarate
23.54
d
Malate  oxaloacetate
23.55
d
Fumarate  malate
a)
b)
c)
d)
C6
C6
C5
C4




C6
C5
C4
C4
Characterize each of the citric acid cycle reactions on the left as to type of reaction using the response
list on the right. Responses on the right may be used more than once or need not be used at all.
23.56
a
Isocitrate  -ketoglutarate
23.57
b
Succinate  fumarate
23.58
d
Succinyl CoA  succinate
23.59
a
Malate  oxaloacetate
23.60
c
Fumarate  malate
a)
b)
c)
d)
oxidation of a 2º alcohol
oxidation with FAD as the oxidizing agent
hydration reaction
hydrolysis reaction
For each of the ETC electron carrier characterizations on the left, select the electron carrier’s name
using the response list on the right. Responses on the right may be used more than once or need not be
used at all.
23.61
b
Interacts with molecular O2
23.62
c
Interacts with NADH
23.63
d
Interacts with FADH2
23.64
b
Contains Fe and Cu
23.65
d
Contains Fe but not Cu
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a)
b)
c)
d)
CoQ
cyt a3
FMN
FeSP
270
Chapter 23: Biochemical Energy Production
Test Bank
For each of the ETC electron carriers on the left, select the number of ETC protein complexes with
which it is associated using the response list on the right. Responses on the right may be used more
than once or need not be used at all.
23.66
a
FADH2
23.67
a
NADH
23.68
c
CoQ
23.69
b
cyt c
23.70
a
cyt b
a)
b)
c)
d)
one protein complex
two protein complexes
three protein complexes
four protein complexes
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CHAPTER 24
Carbohydrate Metabolism
Test Bank
TYPE I MULTIPLE-CHOICE QUESTIONS
In each of the following multiple-choice questions, place the letter of the correct response in the blank
at the left. There is only one correct response for each question.
24.1
c
The primary site within the human body where carbohydrate digestion occurs is the
a) mouth.
b) stomach.
c) small intestine.
d) membranes of intestinal mucosal cells.
24.2
b
Which of the following conversions is accomplished by the process of glycolysis?
a) glucose to glycogen
b) glucose to pyruvate
c) starch to glucose
d) pyruvate to glucose
24.3
c
The first two intermediates in the process of glycolysis are, respectively,
a) glucose 6-phosphate and glucose 1-phosphate.
b) glucose 1-phosphate and glucose 6-phosphate.
c) glucose 6-phosphate and fructose 6-phosphate.
d) glucose 1-phosphate and fructose 1-phosphate.
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271
272
Chapter 24: Carbohydrate Metabolism
24.4
b
The transition from the C6 stage of glycolysis to the C3 stage involves the conversion
of the molecule fructose 1,6-bisphosphate into the C3 species
a) dihydroxyacetone and glyceraldehydes.
b) dihydroxyacetone phosphate and glyceraldehyde 3-phosphate.
c) glyceraldehyde and 3-phosphoglycerate.
d) 3-phosphoglycerate and 2-phosphoglycerate.
24.5
c
How many total steps are there in the process of glycolysis?
a) six
b) eight
c) ten
d) twelve
24.6
d
How many glycolysis intermediates are molecules that contain one or more
phosphate groups?
a) two
b) four
c) six
d) nine
24.7
c
How many steps in the glycolysis pathway have a C3 molecule as the reactant?
a) two
b) four
c) six
d) eight
24.8
d
In the human body, under aerobic conditions and anaerobic conditions, respectively,
pyruvate is converted to
a) lactate and ethanol.
b) lactate and acetyl CoA.
c) ethanol and lactate.
d) acetyl CoA and lactate.
24.9
a
Accumulation of which of the following substances is the cause of stiff and sore
muscles after vigorous exercise?
a) lactate
b) pyruvate
c) acetyl CoA
d) glycerate
24.10
c
[Algorithmic]The net yield of ATP from the complete oxidation of one molecule of
glucose is
a) 12.
b) 24.
c) 30.
d) 36.
Test Bank
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Test Bank
Chapter 24: Carbohydrate Metabolism
273
24.11
a
[Algorithmic]The net yield of ATP per glucose molecule during the process of
glycolysis is
a) 2.
b) 4.
c) 8.
d) 12.
24.12
b
The name of the process in which free glucose is converted to glycogen is
a) gluconeogenesis.
b) glycogenesis.
c) glycogenolysis.
d) glycolysis.
24.13
a
Which of the following processes require UTP molecules?
a) formation of glycogen from glucose
b) degradation of glycogen to glucose
c) both the formation and degradation of glycogen
d) formation of glucose 1-phosphate from glucose 6-phosphate
24.14
c
[Algorithmic]Glucose 1-phosphate is converted to glucose 6-phosphate in which of
the following processes?
a) gluconeogenesis
b) glycogenesis
c) glycogenolysis
d) glycolysis
24.15
a
[Algorithmic]Adding a single glucose unit to a growing glycogen chain
a) requires the investment of 2 ATP molecules.
b) results in the production of 1 ATP molecule.
c) does not require any triphosphate molecules.
d) requires NAD+ as an oxidizing agent.
24.16
c
[Algorithmic]Which of the following intermediates is involved in gluconeogenesis
but not in glycolysis?
a) glucose 1-phosphate
b) pyruvate
c) oxaloacetate
d) phosphoenolpyruvate
24.17
a
[Algorithmic]Which of the following is a reactant in the first step of
gluconeogenesis?
a) carbon dioxide
b) molecular oxygen
c) glucose
d) acetyl CoA
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Chapter 24: Carbohydrate Metabolism
24.18
b
Which of the following substances are participants in the reactions encompassed by
the Cori cycle?
a) pyruvate and acetyl CoA
b) pyruvate and lactate
c) lactate and acetyl CoA
d) pyruvate, lactate and acetyl CoA
24.19
b
[Algorithmic]Which of the following statements concerning the pentose phosphate
pathway is incorrect?
a) It is an alternative pathway to glycolysis for the degradation of glucose.
b) The major coenzyme produced by the pathway is NADH.
c) Pentose derivatives needed for the production of nucleic acids are products of
the pathway.
d) In the first stage of the pathway, glucose 6-phosphate is converted to ribulose
5-phosphate.
24.20
a
Which of the following hormones promotes the uptake and use of glucose by cells?
a) insulin
b) glucagon
c) epinephrine
d) adrenaline
Test Bank
TYPE II MULTIPLE-CHOICE QUESTIONS
In each of the following multiple-choice questions, place the letter of the correct response in the blank
at the left. There may be more than one correct response (choice d) or no correct response for a
question (choice e).
24.21
c
Which of the following statements concerning glycolysis is incorrect?
a) It is an oxidation process in which no molecular oxygen is used.
b) All reactions take place in the cytosol of a cell.
c) There are two stages, each of which involves a series of five reactions.
d) more than one correct response
e) no correct response
24.22
d
In two of the first three steps of glycolysis,
a) phosphorylation reactions occur.
b) isomerization reactions occur.
c) ATP is converted to ADP.
d) more than one correct response
e) no correct response
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Test Bank
Chapter 24: Carbohydrate Metabolism
275
24.23
a
Which of the following C6 stage glycolysis intermediates is paired with the correct
type of enzyme needed for its production?
a) glucose 6-phosphate; kinase
b) fructose 6-phosphate; dehydrogenase
c) fructose 1,6-bisphosphate; mutase
d) more than one correct response
e) no correct response
24.24
b
In which of the following steps of glycolysis does substrate-level phosphorylation
occur?
a) production of phosphoenolpyruvate
b) production of pyruvate
c) production of 2-phosphoglycerate
d) more than one correct response
e) no correct response
24.25
d
Which of the following C3 stage glycolysis intermediates undergoes an isomerization
reaction?
a) dihydroxyacetone phosphate
b) glyceraldehyde 3-phosphate
c) 3-phosphoglycerate
d) more than one correct response
e) no correct response
24.26
b
Intermediates in the glycolysis pathway include
a) two glucose derivatives.
b) three glycerate derivatives.
c) two pyruvate derivatives.
d) more than one correct response
e) no correct response
24.27
d
The regeneration of NAD+ from NADH occurs during the conversion of pyruvate to
a) lactate.
b) ethanol.
c) acetyl CoA.
d) more than one correct response
e) no correct response
24.28
d
Carbon dioxide is a product when lactate is converted to
a) pyruvate.
b) ethanol.
c) acetyl CoA.
d) more than one correct response
e) no correct response
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276
Chapter 24: Carbohydrate Metabolism
24.29
b
In which of the following processes is glucose the end product?
a) glycogenesis
b) glycogenolysis
c) glycolysis
d) more than one correct response
e) no correct response
24.30
d
Which of the following is a three-step process?
a) conversion of pyruvate to glucose
b) conversion of glucose to glycogen
c) conversion of glycogen to glucose
d) more than one correct response
e) no correct response
24.31
a
The compound glucose 1-phosphate is encountered in which of the following
processes?
a) glycogenesis and glycogenolysis
b) glycolysis and gluconeogenesis
c) glycogenesis and gluconeogenesis
d) more than one correct response
e) no correct response
24.32
e
The compound glucose 6-phosphate is not encountered in which of the following
processes?
a) conversion of pyruvate to glucose
b) conversion to glucose to pyruvate
c) conversion of glycogen to glucose
d) more than one correct response
e) no correct response
24.33
b
The compound oxaloacetate is an intermediate in the conversion of
a) glycogen to glucose.
b) pyruvate to glucose.
c) pyruvate to acetyl CoA.
d) more than one correct response
e) no correct response
24.34
d
Which of the following is a product of the first stage of the pentose phosphate
pathway?
a) carbon dioxide
b) a phosphorylated version of the coenzyme NADH
c) ribose 5-phosphate
d) more than one correct response
e) no correct response
Test Bank
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Test Bank
24.35
c
Chapter 24: Carbohydrate Metabolism
277
Which of the following hormones increases blood glucose levels?
a) insulin and glucagon
b) insulin and epinephrine
c) glucagon and epinephrine
d) more than one correct response
e) no correct response
MULTIPLE-CHOICE FORMAT TRUE-FALSE QUESTIONS
In each of the following multiple-choice questions, characterize EACH of the three given statements
as being TRUE or FALSE and then indicate the collective true-false status of the statements using the
choices
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
24.36 c - FTF Statements:
(1) The three major monosaccharide products from carbohydrate digestion are
glucose, galactose, and ribose.
(2) In glycolysis, two ATP molecules are consumed and four ATP molecules are
produced.
(3) The Cori cycle is a process in which glucose is converted to pyruvate which is
then converted back to glucose.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
24.37 b - FTT
Statements:
(1) Glycogenesis and glycolysis are “opposite” processes.
(2) The focal point for carbohydrate metabolism is the molecule glucose.
(3) Production of 30 ATP molecules accompanies the complete oxidation of a
glucose molecule.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
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278
Chapter 24: Carbohydrate Metabolism
24.38 b - FTT
Test Bank
Statements:
(1) Absorption of monosaccharides through the intestinal wall into the
bloodstream involves passive transport.
(2) In the conversion of pyruvate to acetyl CoA, a carbon dioxide molecule is
produced.
(3) Glucose degradation occurs in both glycolysis and the pentose phosphate
pathway.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
24.39 c - FTF Statements:
(1) The process of glycolysis converts a C6 molecules into three C2 molecules.
(2) The primary location where gluconeogenesis occurs is the liver.
(3) Pyruvate reduction to lactate occurs under aerobic conditions, and pyruvate
oxidation to acetyl CoA results from anaerobic conditions.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
24.40 a - TTT Statements:
(1) Glucose 1-phosphate is an intermediate in both glycogenesis and
glycogenolysis.
(2) Conversion of ATP to ADP occurs in both steps 1 and 3 of glycolysis.
(3) In the oxidative stage of the pentose phosphate pathway, a hexose phosphate is
converted to a pentose phosphate and carbon dioxide.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
24.41 b - TTF Statements:
(1) Gluconeogenesis is a process through which glucose can be synthesized from
noncarbohydrate materials.
(2) The process of glycolysis takes place in the cytosol of a cell.
(3) Insulin’s function is to increase blood glucose levels by speeding up the
conversion of glycogen to glucose.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
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Test Bank
24.42 b - TFT
Chapter 24: Carbohydrate Metabolism
279
Statements:
(1) All intermediates in the C3 stage of glycolysis are phosphorylated derivatives
of either glycerol or acetone.
(2) The digestion of carbohydrates begins in the mouth, continues in the stomach,
and is completed in the small intestine.
(3) The storage form for excess glucose in the body is glycogen produced by
glycogenesis.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
24.43 a - TTT Statements:
(1) The conversion of glucose 6-phosphate to glucose, the last step of
glycogenolysis, does not occur in muscle and brain cells.
(2) The two triose phosphates initially formed in glycolysis are dihydroxyacetone
phosphate and glyceraldehyde 3-phosphate.
(3) ATP production during glycolysis occurs via substrate-level phosphorylation.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
24.44 d - FFF Statements:
(1) The first step of glycolysis involves the phosphorylation of glucose to produce
glucose 1-phosphate.
(2) The processing of one glucose molecule via glycolysis produces two acetyl
CoA molecules and two carbon dioxide molecules.
(3) The majority of ATP molecules produced during the complete oxidation of
glucose form during the glycolysis phase of oxidation.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
24.45 a - TTT Statements:
(1) Lactate accumulation is the cause of muscle pain and cramping during
prolonged, strenuous exercise.
(2) Lactate production during exercise lowers blood pH, which triggers faster
breathing.
(3) The effects of both type I and type II diabetes are the same - inadequate
glucose uptake by cells.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
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280
Chapter 24: Carbohydrate Metabolism
Test Bank
MATCHING QUESTIONS
Assign each of the characterizations on the left to one of the metabolic pathways listed in the response
list on the right. Responses on the right may be used more than once or need not be used at all.
24.46
d
Glucose is converted to two pyruvates.
24.47
b
Glycogen is synthesized from glucose.
24.48
c
Glycogen is broken down into free glucose units.
24.49
a
Glucose is synthesized from pyruvate.
24.50
a
Two C3 molecules combine to give a C6 molecule.
a)
b)
c)
d)
gluconeogenesis
glycogenesis
glycogenolysis
glycolysis
Assign each of the reaction characterizations on the left to one of the metabolic pathways listed in the
responses on the right. Responses on the right may be used more than once or need not be used at all.
24.51
d
Fructose 6-phosphate is the product formed in the
second step of this process.
24.52
b
Formation of UDP-glucose is part of this process.
24.53
a
Oxaloacetate is the product formed in the first step
of this process.
24.54
a
Two trioses combine to form fructose
1,6-bisphosphate as part of this process.
24.55
b
Glucose 6-phosphate is converted to glucose
1-phosphate as part of this process.
a)
b)
c)
d)
gluconeogenesis
glycogenesis
glycogenolysis
glycolysis
How many steps in glycolysis have the characteristics listed on the left? Respond using the response
list on the right. Responses on the right may be used more than once or need not be used at all.
24.56
b
ATP is converted to ADP.
a)
b)
c)
d)
24.57
c
An isomerization reaction occurs.
24.58
b
Substrate-phosphorylation occurs.
24.59
b
A bisphosphate molecule is formed.
24.60
c
A glycerate derivative is formed.
one step
two steps
three steps
four steps
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Test Bank
Chapter 24: Carbohydrate Metabolism
281
What is the ATP yield per glucose molecule in each of the following processes? Respond using the
list on the right. Responses on the right may be used more than once or need not be used at all.
24.61
a
Glycolysis
24.62
d
Glycolysis plus the common metabolic pathway
24.63
a
Glycolysis plus oxidation of pyruvate to acetyl CoA
24.64
a
Glycolysis plus reduction of pyruvate to lactate
24.65
a
Glycolysis plus reduction of pyruvate to ethanol
a)
b)
c)
d)
2 ATP
4 ATP
10 ATP
30 ATP
For each of the chemical changes on the left, choose from the response list on the right a correct name
for the process or the conditions under which it occurs. Responses on the right may be used more than
once or need not be used at all.
24.66
b
Pyruvate to lactate
24.67
b
Pyruvate to ethanol
24.68
a
Glucose to pyruvate to lactate to pyruvate to
glucose
24.69
c
Glucose 6-phosphate to ribulose 5-phosphate
24.70
d
Ribulose 5-phosphate to ribose 5-phosphate
Copyright © Houghton Mifflin Company. All rights reserved.
a) Cori cycle
b) an anaerobic process
c) oxidative stage of pentose
phosphate pathway
d) nonoxidative stage of
pentose phosphate pathway
CHAPTER 25
Lipid Metabolism
Test Bank
TYPE I MULTIPLE-CHOICE QUESTIONS
In each of the following multiple-choice questions, place the letter of the correct response in the blank
at the left. There is only one correct response for each question.
25.1
b
The two major products of triacylglycerol digestion in the small intestine are fatty
acids and
a) glycerol.
b) monoacylglycerols.
c) diacylglycerols.
d) acetyl CoA.
25.2
c
The major function for bile released during the digestion of triacylglycerols is to
a) facilitate the formation of chyme.
b) act as an enzyme.
c) act as an emulsifier.
d) hydrolyze ester linkages within triacylglycerols.
25.3
a
Lipoproteins that transport triacylglycerols from intestinal cells to the bloodstream
are called
a) chylomicrons.
b) fatty acid micelles.
c) adipocytes.
d) chymes.
282
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Test Bank
Chapter 25: Lipid Metabolism
283
25.4
c
How many times do dietary triacylglycerols undergo hydrolysis before they become
available for use by cells?
a) one
b) two
c) three
d) four
25.5
b
The first stage of glycerol metabolism involves a two-step process in which the
glycerol is converted to
a) glycerol 3-phosphate.
b) dihydroxyacetone phosphate.
c) 3-phosphoglycerate.
d) 2-phosphoglycerate.
25.6
a
Before a fatty acid can enter the fatty acid spiral, it must be activated and then
shuttled across the inner mitochondrial membrane. The activating agent and shuttle
molecule are, respectively,
a) CoA and carnitine.
b) CoA and citrate.
c) acetyl CoA and carnitine.
d) acetyl CoA and citrate.
25.7
b
The correct sequence for the four reactions of the fatty acid spiral in terms of
“functional group acted upon” is
a) alkene, alkane, ketone, 2º alcohol.
b) alkane, alkene, 2º alcohol, ketone.
c) alkane, ketone, 2º alcohol, alkene.
d) ketone, 2º alcohol, alkene, alkane.
25.8
b
The correct sequence for the four reactions of the fatty acid spiral in terms of “type of
reaction occurring” is
a) dehydrogenation, dehydrogenation, hydration, chain cleavage.
b) dehydrogenation, hydration, dehydrogenation, chain cleavage.
c) chain cleavage, hydration, dehydration, dehydrogenation.
d) chain cleavage, dehydration, hydration, dehydration.
25.9
a
[Algorithmic]How many turns of the fatty acid spiral are needed to “process” a C14
fatty acid molecule?
a) six
b) seven
c) twelve
d) fourteen
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284
Chapter 25: Lipid Metabolism
25.10
a
[Algorithmic]How many FADH2 and NADH molecules are produced, respectively,
during one turn of the fatty acid cycle?
a) 1, 1
b) 1, 2
c) 2, 1
d) 1, 3
25.11
a
[Algorithmic]What is the net ATP production for the complete degradation of a C14
fatty acid molecule to CO2 and H2O?
a) 92
b) 106
c) 120
d) 134
25.12
a
The starting material for the process of ketogenesis is
a) acetyl CoA.
b) oxaloacetate.
c) pyruvate.
d) citrate.
25.13
c
Three of the following four compounds are classified as ketone bodies. The one that
is not is
a) acetoacetate.
b) -hydroxybutyrate.
c) acetobutyrate.
d) acetone.
25.14
b
The notation ACP stands for
a) acyl carnitine pyruvate.
b) acyl carrier protein.
c) acetyl carnitine pyruvate.
d) acetyl carrier protein.
25.15
a
The reducing agent needed in the process of lipogenesis is
a) NADPH.
b) NADH.
c) FADH2.
d) ADP.
25.16
d
The carrier of the “two carbon units” used to biosynthesize a fatty acid is
a) acetyl CoA.
b) acetyl ACP.
c) malonyl CoA.
d) malonyl ACP.
Test Bank
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Test Bank
Chapter 25: Lipid Metabolism
285
25.17
d
Which of the following processes requires molecular O2 as a reactant?
a) saturated fatty acid degradation to acetyl CoA
b) saturated fatty acid biosynthesis
c) unsaturated fatty acid degradation to acetyl CoA
d) unsaturated fatty acid biosynthesis
25.18
c
[Algorithmic]Which of the following is a correct ordering of cholesterol
intermediates as they are encountered during the biosynthesis of cholesterol?
a) mevalonate, lanosterol, squalene, isopentenyl pyrophosphate
b) lanosterol, squalene, isopentenyl pyrophosphate, mevalonate
c) mevalonate, isopentenyl pyrophosphate, squalene, lanosterol
d) squalene, isopentenyl pyrophosphate, mevalonate, lanosterol
25.19
a
[Algorithmic]Which of the following statements concerning “fuel usage” in the
human body is incorrect?
a) Skeletal muscle in a resting state uses glucose.
b) Cardiac muscle primarily uses fatty acids.
c) Brain function is maintained primarily by glucose.
d) Red blood cells use only glucose.
25.20
b
Which of the following chemical changes is not possible within the human body?
a) pyruvate to acetyl CoA
b) acetyl CoA to pyruvate
c) fatty acid to CO2 and H2O via acetyl CoA, the CAC, and the ETC
d) glucose to fatty acid via acetyl CoA
TYPE II MULTIPLE-CHOICE QUESTIONS
In each of the following multiple-choice questions, place the letter of the correct response in the blank
at the left. There may be more than one correct response (choice d) or no correct response for a
question (choice e).
25.21
b
Which of the following statements concerning digestion of dietary triacylglycerols in
adults is correct?
a) Triacylglycerol digestion begins in the mouth.
b) Triacylglycerol digestion occurs to a small extent (10%) in the stomach.
c) Triacylglycerol digestion occurs only in the small intestine.
d) more than one correct response
e) no correct response
25.22
a
Which of the following is a lipoprotein?
a) chylomicrons
b) fatty acid micelles
c) adipocytes
d) more than one correct response
e) no correct response
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286
Chapter 25: Lipid Metabolism
25.23
e
Which of the following compounds is an intermediate in the conversion of glycerol to
dihydroxyacetone phosphate?
a) acetoacetate
b) acetone
c) 3-phosphoglycerate
d) more than one correct response
e) no correct response
25.24
c
The molecule carnitine is involved in
a) glycerol catabolism.
b) fatty acid activation.
c) a shuttle system for acyl CoA.
d) more than one correct response
e) no correct response
25.25
b
Which of the following pairings of terms is correct for reactions in the fatty acid
spiral?
a) alkene functional group; dehydrogenation
b) ketone functional group; chain cleavage
c) alkane functional group; hydration
d) more than one correct response
e) no correct response
25.26
d
One turn of the fatty acid spiral produces
a) an acetyl CoA molecule.
b) two molecules of ATP.
c) an acyl CoA molecule that has been shortened by two carbon atoms.
d) more than one correct response
e) no correct response
25.27
a
Which of the following relationships involving turns of the fatty acid spiral are
correct?
a) 8 turns; 9 acetyl CoA molecules
b) 7 turns; 8 NADH molecules
c) 6 turns; 7 FADH2 molecules
d) more than one correct response
e) no correct response
25.28
d
Which of the following enzymes are required for processing unsaturated fatty acids
through the fatty acid spiral but not for processing saturated fatty acids through the
spiral?
a) an epimerase to change a D-isomer to a L-isomer
b) an isomerase to change a cis (3, 4) bond to a trans (2, 3) bond
c) a transferase to change a -hydroxyacyl CoA to a -hydroxyacyl CoA
d) more than one correct response
e) no correct response
Test Bank
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Test Bank
Chapter 25: Lipid Metabolism
287
25.29
e
Which of the following generalizations about “fuel” use in the human body is
incorrect?
a) Skeletal muscle in an active state uses fatty acids.
b) Skeletal muscle in a resting state uses glucose.
c) Heart muscle uses glucose as a preferred fuel.
d) more than one correct response
e) no correct response
25.30
a
Which of the following compounds is a ketone body?
a) acetoacetate
b) oxaloacetate
c) acetyl CoA
d) more than one correct response
e) no correct response
25.31
d
Which of the following statements concerning lipogenesis is correct?
a) It occurs in the cytosol of a cell.
b) It involves a multienzyme complex rather than a series of individual enzymes.
c) It is dependent on the oxidizing agents FAD and NAD+.
d) more than one correct response
e) no correct response
25.32
a
Which of the following statements concerning the chain elongation phase of fatty
acid biosynthesis is correct?
a) Step 1 involves a condensation reaction.
b) Step 2 involves a hydration reaction.
c) Step 3 involves a dehydrogenation reaction.
d) more than one correct response
e) no correct response
25.33
b
Which of the following is an intermediate in the process of lipogenesis?
a) isopentenyl pyrophosphate
b) malonyl ACP
c) oxaloacetate
d) more than one correct response
e) no correct response
25.34
c
Which of the following pairings of information about intermediates in the
biosynthesis of cholesterol is correct?
a) mevalonate; a C5 molecule
b) squalene; a C20 molecule
c) lanosterol; a C30 molecule
d) more than one correct response
e) no correct response
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288
Chapter 25: Lipid Metabolism
25.35
d
Test Bank
Which of the following is a possible fate for the acetyl CoA produced from the
degradation of a fatty acid?
a) conversion to pyruvate
b) ketone body formation
c) cholesterol biosynthesis
d) more than one correct response
e) no correct response
MULTIPLE-CHOICE FORMAT TRUE-FALSE QUESTIONS
In each of the following multiple-choice questions, characterize EACH of the three given statements
as being TRUE or FALSE and then indicate the collective true-false status of the statements using the
choices
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
25.36 b - TTF Statements:
(1) Both TAG emulsification and TAG digestion occur in the small intestine.
(2) On an equal-mass basis, fatty acids produce more than twice as much ATP per
gram as carbohydrates (glucose).
(3) The “opposite” processes of lipogenesis and fatty acid oxidation cannot occur
at the same time.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
25.37 b - TTF Statements:
(1) The fatty acid spiral involves a repetitive series of four reactions.
(2) Triacylglycerol mobilization is a hydrolysis process that occurs in adipose
tissue.
(3) ATP and ACP have similar functions within the human body.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
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Test Bank
25.38 c - FFT
Chapter 25: Lipid Metabolism
289
Statements:
(1) The process by which ketone bodies are produced from acetyl CoA is called
ketosis.
(2) The number of turns of the fatty acid spiral needed to process an eighteen
carbon saturated fatty acid is nine.
(3) Glycerol metabolism involves production of dihydroxyacetone phosphate,
which then enters the glycolysis pathway.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
25.39 c - TFF Statements:
(1) Initial triacylglycerol digestion usually produces monoacylglycerols rather
than glycerol itself.
(2) Fatty acids are the preferred fuel for “running” the heart (cardiac muscle) and
the brain.
(3) The ketone body acetoacetate is the “parent” compound for the other four
ketone bodies.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
25.40 c - TFF Statements:
(1) The number of acetyl CoA molecules produced in the fatty acid spiral is equal
to half the number of carbon atoms in the fatty acid that is processed.
(2) A fatty acid micelle is a lipoprotein that transports TAGs from the intestinal
walls to the bloodstream.
(3) Associated with the conversion of acetyl CoA to malonyl CoA, in lipogenesis,
is the production of a carbon dioxide molecule.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
25.41 a - TTT Statements:
(1) The products of the first two stages of cholesterol biosynthesis are,
respectively, mevalonate (C6) and isopentenyl pyrophosphate (C5).
(2) Over 90% of total dietary lipids are triacylglycerols.
(3) The activation stage of fatty acid oxidation involves both CoA and ATP.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
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290
Chapter 25: Lipid Metabolism
25.42 b - FTT
Test Bank
Statements:
(1) The functional group change sequence “alkane-alkene-primary alcoholketone” occurs during each turn of the fatty acid spiral.
(2) Squalene and lanosterol, intermediates in cholesterol biosynthesis, contain
more carbon atoms than does cholesterol.
(3) The acetyl CoA needed for lipogenesis is shuttled from mitochondria to the
cytosol via a citrate shuttle.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
25.43 b - TTF Statements:
(1) When the amount of acetyl CoA is excessive compared with the amount of
oxaloacetate available to react with it, ketone body formation occurs.
(2) The transport stage of fatty acid oxidation involves the shuttle molecule acyl
carnitine.
(3) As a part of digestion of lipids, enzymes in bile help “solubilize” the lipids.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
25.44 c - TFF Statements:
(1) The ketone body acetoacetate lowers blood pH because of the presence of a
carboxyl (acid) group in its structure.
(2) Two products of the initial turn of the fatty acid spiral are acetyl CoA and a
fatty acid that contains two more carbon atoms than the reactant fatty acid.
(3) Fatty acids produced through lipogenesis cannot contain more than fourteen
carbon atoms.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
25.45 a - TTT Statements:
(1) The human body, in the resting state, burns more fat than carbohydrate.
(2) The initial stages of exercise are fueled primarily by glucose.
(3) Statins lower plasma concentrations of LDL by inhibiting cholesterol synthesis
in the liver.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
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Test Bank
Chapter 25: Lipid Metabolism
291
MATCHING QUESTIONS
Identify the step (1 through 4) in a turn of the fatty acid spiral at which each of the compounds on the
left would be encountered as a reactant using the response list on the right. Responses on the right
may be used more than once or need not be used at all.
O
25.46
a
CH3 CH2 CH2 CH2 CH2 C S CoA
OH
25.47
c
CH3 CH2 CH2 CH
O
a)
b)
c)
d)
step 1
step 2
step 3
step 4
CH2 C S CoA
O
25.48
b
CH3 CH
O
25.49
d
CH3 C
OH
25.50
c
CH3 CH
CH
C S CoA
O
CH2 C S CoA
O
CH2 C S CoA
The following questions relate to the degradation of a 16-carbon saturated fatty acid through the fatty
acid spiral to acetyl CoA and the further degradation of the acetyl CoA to carbon dioxide and water.
For each question select an appropriate response from the response list on the right. Responses on the
right may be used more than once or need not be used at all.
25.51
a
How many turns of the fatty acid spiral are needed?
25.52
b
How many acetyl CoA are produced?
25.53
a
How many FADH2 are produced?
25.54
a
How many NADH are produced?
25.55
c
What is the net ATP production for complete degradation of
the fatty acid to CO2 and H2O?
Copyright © Houghton Mifflin Company. All rights reserved.
a)
b)
c)
d)
7
8
106
108
292
Chapter 25: Lipid Metabolism
Test Bank
On the left are characteristics of various reactions that occur in the chain elongation phase of fatty
acid biosynthesis. Identify the step (1 through 4) of the chain elongation process to which each
characterization applies using the response list on the right. Responses on the right may be used more
than once or need not be used at all.
25.56
a
Malonyl ACP is a reactant.
a)
b)
c)
d)
25.57
a
CO2 is a product.
25.58
c
A dehydration reaction occurs.
25.59
d
A carbon-carbon double bond is converted to a carboncarbon single bond.
25.60
a
ACP is a product.
step 1
step 2
step 3
step 4
For each of the substances on the left, select from the response list on the right the process with which
it is associated. Responses on the right may be used more than once or need not be used at all.
25.61
b
Acetoacetyl ACP
25.62
c
Carnitine
25.63
d
Dihydroxyacetone phosphate
25.64
d
Glycerol 3-phosphate
25.65
b
Malonyl CoA
a)
b)
c)
d)
ketogenesis
lipogenesis
fatty acid spiral
glycerol degradation
For each of the substances on the left, which are associated with the biosynthesis of cholesterol, select
the number of carbon atoms present in the substance using the response list on the right. Responses
on the right may be used more than once or need not be used at all.
25.66
d
Squalene
25.67
a
Isopentenyl pyrophosphate
25.68
d
Lanosterol
25.69
b
Mevalonate
25.70
c
Cholesterol
a)
b)
c)
d)
C5 molecule
C6 molecule
C27 molecule
C30 molecule
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CHAPTER 26
Protein Metabolism
Test Bank
TYPE I MULTIPLE-CHOICE QUESTIONS
In each of the following multiple-choice questions, place the letter of the correct response in the blank
at the left. There is only one correct response for each question.
26.1
a
With a normal diet, the percentage of daily calories that come from proteins is about
a) 10%.
b) 20%.
c) 30%.
d) 40%.
26.2
c
As dietary protein materials leave the stomach, they
a) are approximately 50% free amino acids.
b) are approximately 90% free amino acids.
c) are a mixture of large polypeptides.
d) have been denatured but no peptide bond cleavage has occurred.
26.3
a
The dominant use for the amino acids of the amino acid pool is the synthesis of
a) protein.
b) nonprotein nitrogen compounds.
c) nonessential amino acids.
d) pyruvate for energy production.
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26.4
d
The most abundant amino acid in the amino acid pool is
a) alanine.
b) aspartate.
c) cysteine.
d) glutamate.
26.5
a
[Algorithmic]The reactants in a transamination reaction are
a) a ketoacid and an amino acid.
b) an amino acid and glycerol.
c) a ketoacid and ammonia.
d) acetyl CoA and ammonium ion.
26.6
a
[Algorithmic]The products in a transamination reaction are
a) a ketoacid and an amino acid.
b) an amino acid and glycerol.
c) a ketoacid and ammonia.
d) acetyl CoA and ammonium ion.
26.7
b
The net overall effect of transamination reactions in the human body is to collect the
amino groups from a variety of amino acids into a single compound which is
a) a keto acid.
b) an amino acid.
c) acyl carrier protein.
d) carbamoyl phosphate.
26.8
b
[Algorithmic]If pyruvate was a reactant in a transamination reaction one of the
products of the reaction would be
a) glutamate.
b) alanine.
c) aspartate.
d) cysteine.
26.9
a
The nitrogen-containing product of oxidative deamination is
a) ammonium ion.
b) carbamoyl phosphate.
c) isopentenyl pyrophosphate.
d) FADH2.
26.10
a
A derivative of pyridoxine (vitamin B6) is required as a coenzyme in
a) transamination.
b) oxidative deamination.
c) the urea cycle.
d) carbamoyl phosphate formation.
Test Bank
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295
26.11
c
The “fuel” for the urea cycle is
a) ammonium ion.
b) bicarbonate ion.
c) carbamoyl phosphate.
d) acetyl CoA.
26.12
d
Which of the following urea cycle intermediates is incorrectly characterized relative
to its nitrogen content?
a) citrulline; N3 molecule
b) arginine; N4 molecule
c) ornithine; N2 molecule
d) argininosuccinate; N3 molecule
26.13
b
In the urea cycle, the urea-producing step involves the reaction of water with
a) aspartate.
b) arginine.
c) argininosuccinate.
d) carbamoyl phosphate.
26.14
c
The two nitrogen atoms in a urea molecule have as their biosynthetic source
a) two ammonium ions.
b) two aspartate ions.
c) an ammonium ion and an aspartate ion.
d) two acetyl CoA molecules.
26.15
b
The citric acid cycle and the urea cycle are “linked” through the substance
a) malate.
b) fumarate.
c) oxaloacetate.
d) ornithine.
26.16
c
Amino acids with carbon “skeletons” that are degraded to pyruvate are classified as
a) glucogenic.
b) ketogenic.
c) both glucogenic and ketogenic.
d) neither glucogenic nor ketogenic.
26.17
d
Which of the following statements concerning the degradation of amino acid carbon
“skeletons” is correct?
a) Each of the 20 standard amino acids gives a different degradation product.
b) Each of the 20 standard amino acids gives the same degradation product.
c) All final degradation products are citric acid cycle intermediates.
d) Some, but not all, final degradation products are citric acid cycle
intermediates.
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Chapter 26: Protein Metabolism
26.18
c
[Algorithmic]Which of the following statements concerning amino acid
biosynthesis is incorrect?
a) Three amino acids are produced by transamination of the appropriate alphaketo-acid.
b) Starting materials for amino acid biosynthesis are glycolysis intermediates or
citric acid cycle intermediates.
c) All but five of the standard amino acids can be biosynthesized in the human
body.
d) Most bacteria and plants can biosynthesize all of the standard amino acids
often using pathways not present in the human body.
26.19
b
In the degradation of heme, which of the following substances is produced at the
same time that carbon monoxide is produced?
a) bilirubin
b) biliverdin
c) urobilin
d) stercobilin
26.20
a
In the degradation of heme, which of the following substances is produced in the
second step of the degradation process?
a) bilirubin
b) biliverdin
c) urobilin
d) molecular oxygen
Test Bank
TYPE II MULTIPLE-CHOICE QUESTIONS
In each of the following multiple-choice questions, place the letter of the correct response in the blank
at the left. There may be more than one correct response (choice d) or no correct response for a
question (choice e).
26.21
a
Amino acid metabolism differs from that of carbohydrates and triacylglycerols in that
a) there is no storage form for amino acids in the body.
b) amino acids cannot be used for energy production.
c) amino acids cannot be converted to acetyl CoA.
d) more than one correct response
e) no correct response
26.22
d
Which of the following processes supplies amino acids to the amino acid pool?
a) protein digestion
b) protein turnover
c) amino acid biosynthesis
d) more than one correct response
e) no correct response
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Test Bank
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26.23
a
Which of the following substances is a possible reactant in a transamination reaction?
a) amino acid
b) secondary alcohol
c) saturated carboxylic acid
d) more than one correct response
e) no correct response
26.24
d
Which of the following conversions could occur as part of a transamination reaction?
a) pyruvate to alanine
b) alanine to pyruvate
c) oxaloacetate to glutamate
d) more than one correct response
e) no correct response
26.25
a
The net effect of transamination is to
a) collect the amino groups from a variety of amino acids into a single
compound.
b) convert all nonessential amino acids into essential amino acids.
c) convert all alpha-amino acids into beta-amino acids.
d) more than one correct response
e) no correct response
26.26
a
Which of the following is a reactant in oxidative deamination?
a) water
b) ammonium ion
c) NADH
d) more than one correct response
e) no correct response
26.27
e
Which of the following is a product in oxidative deamination of glutamate?
a) oxaloacetate
b) water
c) pyruvate
d) more than one correct response
e) no correct response
26.28
c
Which of the following statements concerning the compound urea is incorrect?
a) It is a white solid in the pure state.
b) It is very soluble in water.
c) It gives urine its odor and color.
d) more than one correct response
e) no correct response
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Chapter 26: Protein Metabolism
26.29
c
Which of the following compounds is a urea cycle intermediate?
a) carbamoyl phosphate
b) aspartate
c) ornithine
d) more than one correct response
e) no correct response
26.30
d
Which of the following substances is a reactant in the formation of carbamoyl
phosphate?
a) carbon dioxide
b) water
c) ATP
d) more than one correct response
e) no correct response
26.31
a
A urea molecule contains
a) two nitrogen atoms.
b) two carbon atoms.
c) two hydrogen atoms.
d) more than one correct response
e) no correct response
26.32
a
Substances to which amino acid carbon “skeletons” may be degraded include
a) acetyl CoA.
b) citrate.
c) succinate.
d) more than one correct response
e) no correct response
26.33
d
Carbon-containing amino acid degradation products can be converted to
a) glucose.
b) ketone bodies.
c) fatty acids.
d) more than one correct response
e) no correct response
26.34
d
In the first step of the degradation of the heme portion of hemoglobin
a) molecular O2 is needed as a reactant.
b) carbon monoxide is a product.
c) ring opening with the release of an iron atom occurs.
d) more than one correct response
e) no correct response
Test Bank
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Test Bank
26.35
d
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Bile pigments produced from the degradation of the heme portion of hemoglobin are
responsible for
a) the yellow color of urine.
b) the reddish-brown color of feces.
c) the yellow skin color associated with the jaundice condition.
d) more than one correct response
e) no correct response
MULTIPLE-CHOICE FORMAT TRUE-FALSE QUESTIONS
In each of the following multiple-choice questions, characterize EACH of the three given statements
as being TRUE or FALSE and then indicate the collective true-false status of the statements using the
choices
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
26.36 b - TTF Statements:
(1) The net effect of protein digestion is the release of the protein’s constituent
amino acids.
(2) Ammonium ions enter the urea cycle in the form of carbamoyl phosphate.
(3) Glycogenic amino acids have carbon skeletons that are degraded to glucose.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
26.37 b - FTT
Statements:
(1) Excess amino acids are stored in the body for later use in the form of tetra- and
pentapeptides.
(2) The ultimate product of all transamination reactions is the amino acid
glutamate.
(3) The oxygen atom in urea comes from a water molecule that participates in a
hydrolysis reaction.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
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Chapter 26: Protein Metabolism
Test Bank
26.38 a - TTT Statements:
(1) Protein digestion begins in the stomach rather than the small intestine.
(2) In the second step of heme degradation, biliverdin is converted to bilirubin.
(3) In the oxidative deamination of glutamate, alpha-ketoglutarate is one of the
products.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
26.39 c - FFT
Statements:
(1) Properties of the compound urea include yellow color, strong odor, and high
solubility in water.
(2) The amino group acceptor in most transamination reactions is oxaloacetate.
(3) Absorption of amino acids through the intestinal wall requires active transport.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
26.40 b - TTF Statements:
(1) Citric acid cycle intermediates are often the products from amino acid carbon
skeleton degradation.
(2) The net effect of transamination is to collect the amino groups from a variety
of amino acids into a single compound.
(3) All of the reactions of the urea cycle occur within mitochondria.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
26.41 c - FTF Statements:
(1) The source for both nitrogen atoms in a urea molecule is carbamoyl phosphate.
(2) In the second stage of amino acid degradation, ammonium ion is liberated
from glutamate through oxidative deamination.
(3) Dietary protein intake and protein turnover are the body’s only sources for
providing amino acids for the amino acid pool.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
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26.42 a - TTT Statements:
(1) A reactant and a product in the first step of the urea cycle are, respectively,
ornithine and citrulline.
(2) Degradation of heme begins with a ring-opening reaction in which carbon
monoxide is produced.
(3) With a normal diet, only about 10% of our total calories come from protein.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
26.43 c - TFF Statements:
(1) Each of the 20 standard amino acid carbon skeletons undergoes a different
degradation process.
(2) The net effect of the urea cycle is the production of urea from ammonium ions
and acetyl CoA.
(3) In transamination, the amino group of an amino acid is interchanged with the
acid group of an alpha-keto acid.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
26.44 b - TTF Statements:
(1) Stercobilin, a bile pigment, is the substance that gives fecal matter its brown
color.
(2) Glycolysis and citric acid cycle intermediates are the starting materials for
amino acid biosynthesis.
(3) The urea cycle participants arginine and citrulline are both nonstandard amino
acids.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
26.45 a - TTT Statements:
(1) The major organic and inorganic solutes in urine are, respectively, urea and
chloride ion.
(2) Nitric oxide is an extremely reactive gaseous chemical messenger in cells that
is produced from the reaction of oxygen with the amino acid arginine.
(3) The action of nitroglycerin, as a heart medication, is related to NO production.
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
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Test Bank
MATCHING QUESTIONS
On the left are found reactants and the type of reaction they undergo. From the response list on the
right, select the product to which each reactant is converted. Responses on the right may be used more
than once or need not be used at all.
26.46
a
Transamination involving pyruvate
26.47
b
Transamination involving oxaloacetate
26.48
d
Transamination involving glutamate
26.49
c
Transamination involving -ketoglutarate
26.50
d
Oxidative deamination involving glutamate
a)
b)
c)
d)
alanine
aspartate
glutamate
-ketoglutarate
For each of the urea cycle characterizations on the left, select a correct response from the response list
on the right. Responses on the right may be used more than once or need not be used at all.
26.51
a
Reacts with carbamoyl phosphate
a)
b)
c)
d)
26.52
d
Reacts with H2O to produce urea
26.53
b
Reacts with aspartate
26.54
c
Fumarate is a product of its “breakup”
26.55
d
Is one of the standard amino acids
ornithine
citrulline
argininosuccinate
arginine
On the left are found the degradation products for particular amino acid carbon “skeletons.” Use the
response list on the right to characterize each amino acid in terms of ketogenicity and glucogenicity.
26.56
a
Acetyl CoA only
26.57
a
Both acetyl CoA and acetoacetyl CoA
26.58
c
Pyruvate only
26.59
b
Succinyl CoA only
26.60
b
Both fumarate and oxaloacetate
a)
b)
c)
d)
ketogenic but not glucogenic
glucogenic but not ketogenic
both ketogenic and glucogenic
neither ketogenic nor glucogenic
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Test Bank
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For each of the heme degradation characterizations on the left, select a correct degradation product
from the response list on the right. Responses on the right may be used more than once or need not be
used at all.
26.61
b
CO is produced at the same time as this substance.
26.62
a
Buildup of this substance in the blood produces jaundice.
26.63
b
Molecular O2 is required as a reactant to produce this
substance.
26.64
c
Substance which gives feces its characteristic color.
26.65
d
Substance which gives urine its characteristic color.
a)
b)
c)
d)
bilirubin
biliverdin
stercobilin
urobilin
In each of the following reactant-product combinations associated with the production of urea,
contrast the nitrogen content of the two compounds using the response list on the right. Responses on
the right may be used more than once or need not be used at all.
26.66
d
Arginine-urea
26.67
d
Arginine-ornithine
26.68
c
Carbamoyl phosphate-citrulline
26.69
a
Ammonium ion-carbamoyl
phosphate
26.70
b
Citrulline-argininosuccinate
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a)
b)
c)
d)
Nitrogen content remains the same.
Nitrogen content increases by one atom.
Nitrogen content increases by two atoms.
Nitrogen content decreases by two atoms.