CHAPTER 5 Essential Concepts of Metabolism
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MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers
the question.
Reference: Page 113 – Metabolism: An Overview
Level of Difficulty: Medium
1.
The synthesis of DNA, in which small nucleotides are joined together to make a single
large molecule would be most correctly described as being a/n ________ reaction.
A) metabolic
B) anabolic
C) catabolic
D) cytobolic
Answer: B
Reference: Page 113 – Metabolism: An Overview
Level of Difficulty: Medium
2.
Oxidation is defined as the ________ while reduction is the ________ .
A) gain of electrons, loss of protons
B) loss of electrons, gain of protons
C) loss of electrons, gain of electrons
D) loss of protons, gain of protons
Answer: C
Reference: Page 113 – Metabolism: An Overview
Level of Difficulty: Medium
3.
Photoautotrophs
A) obtain energy from light and use carbon dioxide as a carbon source
B) obtain energy from organic molecules and use carbon dioxide as a carbon source
C) obtain energy from inorganic substances and use carbon dioxide as a carbon source
D) obtain energy from light and use inorganic substances as a carbon source
Answer: A
Reference: Page 113 – Metabolism: An Overview
Level of Difficulty: Medium
4.
Organisms which get their carbon from other organisms are
A) autotrophs
B) chemotrophs
C) phototrophs
D) heterotrophs
Answer: D
Reference: Page 113 – Metabolism: An Overview
Level of Difficulty: Medium
5.
Animals (humans for example) are
A) photoautotrophs
B) photheterotrophs
C) chemoautotrophs
D) chemoheterotrophs
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Answer: D
Reference: Page 115 – Enzymes
Level of Difficulty: Medium
6.
Enzymes work by
A) lowering the energy of the reactants
B) raising the energy of the productsC) decreasing the activation energy of the reaction
D) increasing the activation energy of the reaction
Answer: C
Reference: Page 116 – Enzymes
Level of Difficulty: Medium
7.
An enzyme-substrate complex forms when substrate binds to an enzyme at the enzyme’s
______ site.
A) catalytic
B) allosteric
C) operative
D) active
Answer: D
Reference: Page 116 – Enzymes
Level of Difficulty: Medium
8.
An enzyme consisting of a protein combined with a non-protein cofactor is known as a
A) simple enzyme
B) apoenzyme
C) holoenzyme
D) coenzyme
Answer: C
Reference: Page 116 – Enzymes
Level of Difficulty: Medium
9.
A holoenzyme consists of
A) an apoenzyme plus a cofactor
B) an apoenzyme plus a coenzyme
C) an protein and non-protein component
D) all of the above
Answer: D
Reference: Page 117 – Enzymes
Level of Difficulty: Medium
10.
An inorganic ion such as zinc or manganese that is needed for an enzyme to function is
acting as a
A) coenzyme
B) cofactor
C) apoenzyme
D) holoenzyme
Answer: B
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Reference: Page 118 – Enzyme Inhibition
Level of Difficulty: Medium
11.
Competitive inhibition of enzymes occurs when
A) the inhibitor binds to the active site of the enzyme
B) the inhibitor binds to the allosteric site of the enzyme
C) the inhibitor changes the shape of the enzyme
D) the inhibitor is acted upon by the enzyme
Answer: A
Reference: Page 118 – Enzyme Inhibition
Level of Difficulty: Medium
12.
Sulfa drugs bind to the active site of the enzyme which normally converts PABA to folic
acid, preventing the production of folic acid and, eventually, purine synthesis. In this
case, the sulfa drug is acting as a/n
A) allosteric inhibitor
B) competitive inhibitor
C) noncompetitive inhibitor
D) uncompetitive inhibitor
Answer: B
Reference: Page 119 – Enzyme Inhibition
Level of Difficulty: Easy
13.
Factors that affect the rate of enzyme catalyzed reactions include
A) temperature
B) pH
C) concentration of enzyme
D) all of the above
Answer: D
Reference: Page 120 – Anaerobic Metabolism: Glycolysis and Fermentation
Level of Difficulty: Medium
14.
The enzymatic breakdown of glucose occurs during
A) gluconeogenesis
B) glycolysis
C) fermentation
D) Kreb’s cycle
Answer: B
Reference: Page 120 – Anaerobic Metabolism: Glycolysis and Fermentation
Level of Difficulty: Medium
15.
In glycolysis each molecule of glucose eventually produces ________ molecules of
pyruvic acid.
A) one
B) two
C) three
D) four
Answer: B
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Reference: Page 120 – Anaerobic Metabolism: Glycolysis and Fermentation
Level of Difficulty: Medium
16.
Substrate level phosphorylation during glycolysis refers to
A) The transfer of phosphate groups from ATP to glucose
B) The transfer of phosphate groups from 1,3 diphosphoglyceric acid to ADP
C) The transfer of phosphate groups from phosphoenolpyruvic acid to ADP
D) The transfer of phosphate groups from ATP to ADP
Answer: A
Reference: Page 121 – Anaerobic Metabolism: Glycolysis and Fermentation
Level of Difficulty: Medium
17.
During glycolysis, fructose a six carbon sugar is broken down into
A) two identical three carbon sugars
B) two different three carbon sugars
C) a four carbon sugar and a two carbon sugar
D) six carbon dioxide molecules
Answer: B
Reference: Page 122 – Anaerobic Metabolism: Glycolysis and Fermentation
Level of Difficulty: Medium
18.
During glycolysis a total of ________ ATP’s are formed with a net yield of ________
ATP’s for each molecule of glucose.
A) eight, four
B) six, four
C) four, four
D) four, two
Answer: D
Reference: Page 122 – Anaerobic Metabolism: Glycolysis and Fermentation
Level of Difficulty: Medium
19.
During glycolysis, electrons are initially transferred to
A) NAD
B) FAD
C) NADP
D) H2O
Answer: A
Reference: Page 122 – Anaerobic Metabolism: Glycolysis and Fermentation
Level of Difficulty: Medium
20.
The end product of glycolysis is
A) fructose-1,6-diphosphate
B) 1,3 diphosphoglyceric acid
C) phosphoenolpyruvic acid
D) pyruvic acid
Answer: D
Reference: Page 122 – Anaerobic Metabolism: Glycolysis and Fermentation
Level of Difficulty: Medium
21.
Pyruvic acid is metabolized in the absence of oxygen during the process of
A) glycolysis
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B) fermentation
C) oxidation
D) reduction
Answer: B
Reference: Page 125 – Aerobic Metabolism: Respiration
Level of Difficulty: Medium
22.
Organisms that can use oxygen for metabolic reactions but can also function in an
environment devoid of oxygen are termed
A) aerobes
B) anaerobes
C) aerophiles
D) facultative anaerobes
Answer: D
Reference: Page 125 – Aerobic Metabolism: Respiration
Level of Difficulty: Easy
23.
Which of the following names does not refer to the Krebs cycle?
A) TCA cycle
B) citric acid cycle
C) tricarboxylic acid cycle
D) glycolytic cycle
Answer: D
Reference: Page 125 – Aerobic Metabolism: Respiration
Level of Difficulty: Medium
24.
The initial substrate molecule for the Krebs cycle is
A) pyruvic acid
B) acetyl-CoA
C) acetic acid
D) butanediol
Answer: B
Reference: Page 126 – Aerobic Metabolism: Respiration
Level of Difficulty: Medium
25.
Each acetyl group that enters the Krebs cycle eventually produces
A) one molecule of carbon dioxide
B) two molecules of carbon dioxide
C) three molecules of carbon dioxide
D) four molecules of carbon dioxide
Answer: B
Reference: Page 125 – Aerobic Metabolism: Respiration
Level of Difficulty: Medium
26.
The electrons transferred from acetyl groups in the Krebs cycle are transferred
A) to NAD only
B) to FAD only
C) to NAD and FAD equally
D) to NAD and FAD unequally
Answer: D
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Reference: Page 122 – Aerobic Metabolism: Respiration
Level of Difficulty: Medium
27.
The final product of glycolysis is
A) pyruvate
B) fructose
C) oxaloacetic acid
D) dihydroxyacetone
Answer: A
Reference: Page 125 – Aerobic Metabolism: Respiration
Level of Difficulty: Medium
28.
During the Krebs cycle, ________ molecules of GTP (which become ATP) are
generated.
A) zero
B) one
C) two
D) three
Answer: C
Reference: Page 125 – Aerobic Metabolism: Respiration
Level of Difficulty: Medium
29.
Each acetyl-CoA molecule will eventually produce ________ in the Krebs cycle.
A) four pairs of electrons
B) three molecules of NAD
C) one molecule of GTP
D) two molecules of pyruvic acid
Answer: B
Reference: Page 128 – Aerobic Metabolism: Respiration
Level of Difficulty: Medium
30.
In the electron transport chain, the energy to make ATP comes directly from
A) FAD
B) NAD
C) both FAD and NAD
D) neither FAD nor NAD
Answer: C
Reference: Page 128 – Aerobic Metabolism: Respiration
Level of Difficulty: Easy
31.
In aerobic respiration, the final electron acceptor is
A) water
B) oxygen
C) sulfur
D) coenzyme Q
Answer: B
Reference: Page 128 – Aerobic Metabolism: Respiration
Level of Difficulty: Hard
32.
The metabolism of a single glucose molecule will deliver ________ pairs of electrons to
the electron transport chain.
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A) four
B) eight
C) twelve
D) sixteen
Answer: C
Reference: Page 125 – Aerobic Metabolism: Respiration
Level of Difficulty: Medium
33.
The prokaryotic aerobic metabolism of glucose produces a total (net) of ________
molecules of ATP.
A) 24
B) 30
C) 34
D) 38
Answer: D
Reference: Page 129 – Aerobic Metabolism: Respiration
Level of Difficulty: Medium
34.
Anaerobic respiration would be indicated by which of the following final electron
acceptors?
A) oxygen
B) pyruvic acid
C) nitrate
D) glucose
Answer: C
Reference: Page 127 – Aerobic Metabolism: Respiration
Level of Difficulty: Medium
35.
In prokaryotic organisms, the electron transport chain can be found in the
A) cell wall
B) cell membrane
C) cytoplasm
D) mitochondria
Answer: B
Reference: Page 130 - Aerobic Metabolism: Respiration
Level of Difficulty: Medium
36.
Which reaction takes place in the mitochondrial matrix?
A) glycolysis
B) fermentation
C) Krebs cycle
D) electron transport
Answer: C
Reference: Page 131- The Metabolism of Fats and Proteins
Level of Difficulty: Medium
37.
During the metabolism of fats, the product of beta oxidation enters
A) glycolysis
B) the Krebs cycle
C) oxidative phosphorylation
D) electron transport chain
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Answer: B
Reference: Page 131- The Metabolism of Fats and Proteins
Level of Difficulty: Hard
38.
Fats are metabolized by
A) glycolysis alone
B) the Krebs cycle alone
C) glycolysis and the Krebs cycle
D) oxidative phosphorylation alone
Answer: C
Reference: Page 132- The Metabolism of Fats and Proteins
Level of Difficulty: Medium
39.
The first step in protein metabolism is the breakdown of proteins into
A) nucleotides
B) fatty acids
C) amino acids
D) coenzymes
Answer: C
Reference: Page 13 2- Other Metabolic Processes
Level of Difficulty: Medium
40.
In photosynthesis, light energy is used to
A) break down proteins
B) phosphorylate ADP to form ATP
C) metabolize glycerol
D) synthesize carbohydrates
Answer: D
Reference: Page 13 2- Other Metabolic Processes
Level of Difficulty: Medium
41.
In photosynthesis, chemical energy is used to make organic molecules in the
A) light reaction
B) dark reaction
C) hydrolytic reaction
D) photophosphorylation reaction
Answer: B
Reference: Page 13 3- Other Metabolic Processes
Level of Difficulty: Medium
42.
In algae, the dark reactions of photosynthesis occur
A) in the cell membrane
B) in the matrix of the mitochondria
C) in the stroma of the chloroplast
D) in the nucleus
Answer: C
Reference: Page 13 3- Other Metabolic Processes
Level of Difficulty: Medium
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43.
Photosynthetic bacteria
A) use chlorophyll a to capture light energy
B) use water for reducing carbon dioxide
C) are usually aerobes
D) contain bacterial chlorophyll
Answer: D
Reference: Page 13 4- Other Metabolic Processes
Level of Difficulty: Medium
44.
Bacteria which can obtain energy from light but are required to use organic substances as
a source of carbon are described as being
A) chemoautotrophs
B) photoheterotrophs
C) photoautotrophs
D) photolithotrophs
Answer: B
Reference: Page 13 4- Other Metabolic Processes
Level of Difficulty: Medium
45.
Bacteria that are able to oxidize inorganic substances for energy but are unable to
photosynthesize are classified as
A) photoautotrophs
B) chemoautotrophs
C) photolithotrophs
D) chemoheterotrophs
Answer: B
Reference: Page 133- Other Metabolic Processes
Level of Difficulty: Medium
46.
What is returned to chlorophyll in cyclic photophosphorylation that is not returned in
noncyclic photoreduction?
A) ATP
B) light
C) energy
D) electrons
Answer: D
Reference: Page 135 – The Uses of Energy
Level of Difficulty: Medium
47.
A metabolic pathway that is involved in both breakdown and synthetic reactions is
properly termed
A) catabolic
B) amphibolic
C) metabolic
D) anabolic
Answer: B
TRUE/FALSE. Write "T" if the statement is true and "F" if the statement is false.
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Reference: Page 113- Metabolism: An Overview
Level of Difficulty: Medium
48.
When one substance is oxidized, another must be reduced.
Answer: True
Reference: Page 113- Metabolism: An Overview
Level of Difficulty: Medium
49.
Autotrophs synthesize organic compounds using carbon dioxide as a carbon source.
Answer: True
Reference: Page 113- Metabolism: An Overview
Level of Difficulty: Medium
50.
Heterotrophs get their energy from sunlight.
Answer: False
Reference: Page 115- Enzymes
Level of Difficulty: Medium
51.
Enzyme catalyzed reactions would not go forward without their specific enzymes.
Answer: False
Reference: Page 115- Enzymes
Level of Difficulty: Medium
52.
Enzymes work by increasing the energy of the reactants.
Answer: False
Reference: Page 116- Enzymes
Level of Difficulty: Medium
53.
Most enzymes catalyze several different reactions.
Answer: False
Reference: Page 117- Enzymes
Level of Difficulty: Medium
54.
Coenzymes are organic molecules while cofactors are inorganic molecules.
Answer: True
Reference: Page 116- Enzymes
Level of Difficulty: Medium
55.
A holoenzyme is an apoenzyme that is missing its cofactor.
Answer: False
Reference: Page 118-Enzyme Inhibition
Level of Difficulty: Medium
56.
Competitive inhibitors bind to the allosteric site of enzymes.
Answer: False
Reference: Page 119-Enzyme Inhibition
Level of Difficulty: Hard
57.
Enzymes become less efficient as temperatures drop because they begin to denature.
Answer: False
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Reference: Page 122-– Aerobic Metabolism: Respiration
Level of Difficulty: Medium
58.
In glycolysis, a total of four ATP molecules are formed per molecule of glucose.
Answer: True
Reference: Page 122– Aerobic Metabolism: Respiration
Level of Difficulty: Medium
59.
Fermentation of pyruvic acid always results in the same end products.
Answer: False
Reference: Page 132- Other Metabolic Processes
Level of Difficulty: Medium
60.
All types of nutrients will enter the Krebs cycle at some point in their catabolism.
Answer: True
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the
question.
Reference: Page 113-Enzymes
Level of Difficulty: Easy
61.
________ is the sum of all the chemical processes carried out by living organisms.
Answer: metabolism
Reference: Page 113- Enzymes
Level of Difficulty: Medium
62.
Reduction is defined as the ________ of electrons.
Answer: loss
Reference: Page 113 -Enzymes
Level of Difficulty: Medium
63.
Organisms that obtain energy from light and carbon from other organisms are classified
as ________.
Answer: photoheterotrophs
Reference: Page 116 -Enzymes
Level of Difficulty: Medium
64.
Enzymes which are synthesized in the cell but act in the periplasmic space are
called________.
Answer: exoenzymes
Reference: Page 118-Enzyme Inhibition
Level of Difficulty: Medium
65.
A nonsubstrate molecule that competes for the active site of an enzyme is said to be a
________ inhibitor.
Answer: competitive
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Reference: Page 120– Anaerobic Metabolism: Glycolysis and Fermentation
Level of Difficulty: Medium
66.
During glycolysis, electrons are initially transferred to ________.
Answer: NAD
Reference: Page 130- Aerobic Metabolism: Respiration
Level of Difficulty: Medium
67.
The initial breakdown of glucose takes place in the ________ of an eukaryotic cell.
Answer: cytoplasm
Reference: Page 125– Aerobic Metabolism: Respiration
Level of Difficulty: Medium
68.
The only true substrate of the Krebs cycle is ________.
Answer: acetyl-CoA
Reference: Page 125– Aerobic Metabolism: Respiration
Level of Difficulty: Medium
69.
In the Krebs cycle, ________ is generated instead of ATP.
Answer: GTP
Reference: Page 128– Aerobic Metabolism: Respiration
Level of Difficulty: Hard
70.
The theory of ________ explains how energy is used to synthesize ATP.
Answer: chemiosmosis
Reference: Page 131- The Metabolism of Fats and Proteins
Level of Difficulty: Medium
71.
Fatty acids are broken down into two carbon compounds via ________ oxidation.
Answer: Beta
Reference: Page 134- Other Metabolic Processes
Level of Difficulty: Medium
72.
Bacteria described as being ________ are capable of using energy from light but require
organic substances as carbon sources.
Answer: photoheterotrophic
Reference: Page 135– The Uses of Energy
Level of Difficulty: Medium
73.
An ________ pathway is involved in both synthetic and breakdown reactions.
Answer: amphibolic
Reference: Page 136– The Uses of Energy
Level of Difficulty: Medium
74.
Transmembrane carrier proteins called ________ form channels through the outer
membrane and allow ions to enter the cell via facilitated diffusion.
Answer: porins
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