Brock Biology of Microorganis 15tH edition by. Madigan, Kelly S. Bender, Daniel H. Buckley, W. Matthew Sattley & David A. Stahl-Test Bank
To Purchase
this Complete Test Bank with Answers Click the link Below
If face any problem or
Further information contact us At tbzuiqe@gmail.com
Sample Test
Brock Biology of Microorganisms, 15e (Madigan
et al.)
Chapter 3 Microbial Metabolism
3.1 Multiple Choice Questions
1) The prokaryotic transport system that involves a
substrate-binding protein, a membrane-integrated transporter, and an
ATP-hydrolyzing protein is
1. A)
the ABC transport system.
2. B) group
translocation.
3. C)
symport.
4. D)
simple transport.
Answer: A
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.2
2) The sum of all biosynthetic reactions in a cell is known as
1. A)
metabolism.
2. B)
anabolism.
3. C)
catabolism.
4. D) synthatabolism.
Answer: B
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.1
3) Based on the functional roles of phosphate in various
microbial metabolisms, which of the following compounds most likely contain
phosphate?
1. A)
organic compounds
2. B)
inorganic compounds
3. C)
both organic and inorganic compounds
4. D)
neither organic nor inorganic compounds
Answer: C
Bloom’s Taxonomy: 5-6: Evaluating/Creating
Chapter Section: 3.1
4) Which of the following would be used by a chemoorganotroph
for energy?
1. A)
C2H3O2-
2. B) H2
3. C)
CO2
4. D) H+
Answer: A
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.3
5) Which of the following statements is FALSE?
1. A)
Most bacteria are capable of using ammonia as their sole nitrogen source.
2. B)
Some bacteria are able to use nitrates or nitrogen gas as their nitrogen
source.
3. C)
Most available nitrogen is in organic forms.
4. D)
Nitrogen is a major component of proteins and nucleic acids.
Answer: C
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.6
6) All microorganisms require
1. A)
carbon, iron, and sodium.
2. B)
phosphorus, aluminum, and sodium.
3. C)
calcium, potassium, and magnesium.
4. D)
phosphorus, selenium, and sulfur.
Answer: D
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.1
7) Which element functions BOTH as an enzyme cofactor and as a
stabilizer of ribosomes and nucleic acids?
1. A)
iron
2. B)
hydrogen
3. C)
zinc
4. D)
magnesium
Answer: D
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.1
8) Based on your understanding of metabolism, generalize when an
enzymeʹs rate of activity can be changed.
1. A)
before enzyme production
2. B)
during enzyme production
3. C)
after enzyme production
4. D) at
any point—before, during, or after enzyme production
Answer: C
Bloom’s Taxonomy: 5-6: Evaluating/Creating
Chapter Section: 3.5
9) The change in Gibbs free energy for a particular reaction is
most useful in determining
1. A)
the amount of energy catalysts required for biosynthesis or catabolism.
2. B)
the potential metabolic reaction rate.
3. C)
whether there will be a requirement or production of energy.
4. D)
energy stored in each compound.
Answer: C
Bloom’s Taxonomy: 3-4: Applying/Analyzing
Chapter Section: 3.4
10) Which is an example of a micronutrient?
1. A)
arginine
2. B)
inorganic phosphorous
3. C)
iron
4. D)
vitamin B12
Answer: C
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.1
11) Aseptic technique refers to
1. A)
the microbial inoculum placed into a test tube or onto a Petri plate.
2. B) a
series of practices to avoid contamination.
3. C)
the autoclave and other sterilizing procedures.
4. D)
cleanliness in the laboratory.
Answer: B
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 1.9
12) To ensure growth of a newly discovered bacterium with
unknown nutritional requirements, it would be best to begin with a ________
medium rather than a ________ medium.
1. A)
complex / minimal
2. B)
minimal / complex
3. C)
selective / complex
4. D)
selective / differential
Answer: A
Bloom’s Taxonomy: 5-6: Evaluating/Creating
Chapter Section: 3.2
13) If ΔG0ʹ is negative, the reaction is
1. A)
exergonic and requires the input of energy.
2. B)
endergonic and requires the input of energy.
3. C)
exergonic and energy will be released.
4. D)
endergonic and energy will be released.
Answer: C
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.4
14) Activation energy is the energy
1. A)
required for a chemical reaction to begin.
2. B)
given off as the products in a chemical reaction are formed.
3. C)
absorbed as ΔG0ʹ moves from negative to positive.
4. D)
needed by an enzyme to catalyze a reaction without coenzymes.
Answer: A
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.5
15) A catalyst
1. A)
requires more reactants but makes the reaction rate faster.
2. B)
increases the amount of reactants produced but does not change the rate.
3. C)
changes the rate of the reaction but does not change the end amount of
products.
4. D)
changes both the rate of a reaction and the amount of the product that will be
obtained as
the reaction is completed.
Answer: C
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.5
16) The portion of an enzyme to which substrates bind is
referred to as the
1. A) substrate
complex.
2. B)
active site.
3. C)
catalytic site.
4. D)
junction of van der Waals forces.
Answer: B
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.5
17) What is the difference between a coenzyme and a prosthetic
group?
1. A)
Coenzymes are essential for an enzymeʹs function and prosthetic groups only
enhance its reaction rate.
2. B)
Coenzymes are weakly bound whereas prosthetic groups are strongly bound to
their respective enzymes.
3. C)
Coenzymes are organic cofactors and prosthetic groups are inorganic cofactors.
4. D)
Coenzymes require additional ions to bind to enzymes but prosthetic groups are
able to directly interact with enzymes.
Answer: B
Bloom’s Taxonomy: 3-4: Applying/Analyzing
Chapter Section: 3.5
18) If an oxidation reaction occurs
1. A)
simultaneous reduction of a different compound will also occur, because
electrons do not generally exist alone in solution.
2. B)
another oxidation reaction will occur for a complete reaction, because one
oxidation event is considered a half reaction.
3. C) a
cell is undergoing aerobic respiration, because oxygen is being used.
4. D) a
reduction reaction would not occur, because they are opposite reaction
mechanisms.
Answer: A
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.6
19) The class of macromolecules in microorganisms that
contributes most to biomass is
1. A)
carbohydrates.
2. B)
DNA.
3. C)
lipids.
4. D)
proteins.
Answer: D
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.1
20) A chemoorganotroph and a chemolithotroph in the same
environment would NOT compete for
1. A)
oxygen.
2. B)
carbon.
3. C)
nitrogen.
4. D)
phosphorous.
Answer: B
Bloom’s Taxonomy: 3-4: Applying/Analyzing
Chapter Section: 3.3
21) A chemoorganotroph and a photoautotroph in the same environment
would NOT compete for
1. A)
oxygen.
2. B)
carbon.
3. C)
nitrogen.
4. D)
carbon and oxygen.
Answer: D
Bloom’s Taxonomy: 3-4: Applying/Analyzing
Chapter Section: 3.3
22) The Embden-Meyerhof-Parnas pathway is another name for
1. A)
the citric acid cycle.
2. B)
glycolysis.
3. C)
electron transport.
4. D)
NADH production.
Answer: B
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.8
23) The net gain of ATP per molecule of glucose fermented is
1. A) 1.
2. B) 2.
3. C) 4.
4. D) 8.
Answer: B
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.8
24) Which of the following is a common energy storage polymer in
microorganisms?
1. A)
acetyl~S-CoA
2. B)
glycogen
3. C)
adenosine triphosphate
4. D) H2
Answer: B
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.8
25) Fermentation has a relatively low ATP yield compared to
aerobic respiration because
1. A)
more reducing equivalents are used for anaerobic catabolism.
2. B)
less ATP is consumed during the first stage of aerobic catabolism.
3. C)
oxidative phosphorylation yields a lot of ATP.
4. D)
substrate-level phosphorylation yields a lot of ATP.
Answer: C
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.8
26) From the standpoint of fermentative microorganisms, the
crucial product in glycolysis is
1. A)
ATP and regenerated NAD+; the fermentation products are waste products.
2. B)
ethanol or lactate; ATP is a waste product.
3. C)
CO2; ATP is a waste product.
4. D)
not relevant because glycolysis is not a major pathway.
Answer: A
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.8
27) In aerobic respiration, the final electron acceptor is
1. A)
hydrogen.
2. B)
oxygen.
3. C)
water.
4. D)
ATP.
Answer: B
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.10
28) Which of the following is NOT membrane-associated?
1. A)
NADH dehydrogenases
2. B)
flavoproteins
3. C)
cytochromes
4. D)
Cytochromes, flavoproteins, and NADH dehydrogenases all can be
membrane-associated.
Answer: D
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.10
29) During electron transport reactions
1. A)
OH- accumulates on the outside of the membrane while H+ accumulates on the
inside.
2. B)
OH- accumulates on the inside of the membrane while H+ accumulates on the
outside.
3. C)
both OH- and H+ accumulate on the inside of the membrane.
4. D)
both OH- and H+ accumulate on the outside of the membrane.
Answer: B
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.11
30) The rising of bread dough is the result of
1. A)
biotin production.
2. B)
carbon dioxide produced by fermentation.
3. C)
oxidative phosphorylation.
4. D)
oxygen being released.
Answer: B
Bloom’s Taxonomy: 3-4: Applying/Analyzing
Chapter Section: 3.8
31) Which intermediate compound(s) in the citric acid cycle
is/are often used for biosynthetic pathways as well as carbon catabolism?
1. A)
only α-ketoglutarate
2. B)
only oxaloacetate
3. C)
only succinyl-CoA
4. D)
α-ketoglutarate, oxaloacetate, and succinyl-CoA
Answer: D
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.9
32) Microbial growth on the two-carbon acetate substrate invokes
1. A)
the citric acid cycle for aerobic catabolism.
2. B)
both the citric acid and glyoxylate pathways.
3. C)
the glyoxylate pathway.
4. D)
the glyoxylate and glycolysis pathways.
Answer: B
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.9
33) Which is one major difference between anaerobic and aerobic
respiration?
1. A)
electron donor
2. B)
electron acceptor
3. C)
use of electron transport
4. D)
use of proton motive force
Answer: B
Bloom’s Taxonomy: 3-4: Applying/Analyzing
Chapter Section: 3.12
34) For a carbon source, chemoorganotrophs generally use
compounds such as
1. A)
acetate, succinate, and glucose.
2. B)
bicarbonate and carbon dioxide.
3. C)
nitrate and nitrite.
4. D)
acetate, bicarbonate, and nitrate.
Answer: A
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.3
35) All of the following are non-protein electron carriers
EXCEPT
2. A) FADH2.
3. B)
FMNH2.
4. C)
cytochromes.
5. D)
quinones.
Answer: C
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.10
36) Which two metabolic processes are most dissimilar?
1. A)
citric acid cycle and glycolysis
2. B)
glycolysis and gluconeogenesis
3. C)
proton motive force and substrate-level phosphorylation
4. D)
pentose phosphate pathway and glycolysis
Answer: B
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.13
37) How does the proton motive force lead to production of ATP?
1. A) ATPase
requires one proton to make one ATP.
2. B)
Protons must be pumped against a concentration gradient from outside of the
cell into the cell to rotate the F0 subunit of ATPase for the F1 subunit to
make ATP.
3. C)
Oxidative phosphorylation of ADP by ATP synthase requires protons as cofactors
in the reaction.
4. D)
Translocation of three to four protons drives the F0 component of ATPase which
in turn phosphorylates one ADP into ATP.
Answer: D
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.11
38) Five-carbon sugars are used in the
1. A)
biosynthesis of DNA and RNA.
2. B)
catabolic pentose phosphate pathway for carbon and energy.
3. C)
biosynthesis of DNA and RNA as well as catabolic pentose phosphate pathway.
4. D)
activation of pentoses to form glycogen for energy storage.
Answer: A
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.13
39) Improperly functioning acyl carrier proteins (ACPs) would
likely result in
1. A) a
physiological shift to anaerobic metabolism where an energized membrane is less
important for energy production.
2. B)
enhanced growth of a bacterium due to faster growth substrate uptake by a
weakened membrane.
3. C) no
harm to bacteria, because only archaeons and eukaryotes use ACPs for fatty acid
biosynthesis.
4. D) death
for a bacterium due to poor lipid bilayer integrity.
Answer: D
Bloom’s Taxonomy: 3-4: Applying/Analyzing
Chapter Section: 3.15
40) A bacterium running low on NADPH could ________ to generate
more of this coenzyme.
1. A)
degrade an amino acid or nucleic acid
2. B)
invoke the pentose phosphate pathway
3. C)
degrade a fatty acid
4. D)
use a broad specificity phosphatase with inorganic phosphatase and NADH
Answer: B
Bloom’s Taxonomy: 3-4: Applying/Analyzing
Chapter Section: 3.13
41) One example of an electron acceptor that can be used in
anaerobic respiration is
1. A)
NADH.
2. B)
water.
3. C)
nitrate.
4. D)
FMN.
Answer: C
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.12
42) When culturing a chemoorganoheterophic bacterium, what
outcome is LEAST likely to occur if ammonia and phosphate are provided at equal
concentrations?
1. A)
Cells require much less P to grow than N, so extra P will be used for ATP
synthesis and result in a faster growth rate.
2. B)
Cells will never consume all of the phosphate, because N is needed in higher
quantities than P.
3. C)
The final biomass of cells will be no different than if only 50% of the
phosphate was provided.
4. D)
The bacteria will import all of the ammonia to use for biosynthetic pathways.
Answer: A
Bloom’s Taxonomy: 5-6: Evaluating/Creating
Chapter Section: 3.3
43) Most of the carbon in amino acid biosynthesis comes from
1. A)
citric acid cycle intermediates.
2. B)
citric acid cycle intermediates and glycolysis products.
3. C)
glycolysis products.
4. D) glycolysis
intermediates and products.
Answer: B
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.14
44) Which metabolic cycle or pathway is LEAST likely to be
invoked during the biosynthesis of DNA?
1. A)
citric acid cycle
2. B)
glycolysis
3. C)
gluconeogenesis
4. D)
pentose phosphate pathway
Answer: C
Bloom’s Taxonomy: 5-6: Evaluating/Creating
Chapter Section: 3.14
45) Hypothetically, if free electrons existed in sufficient
numbers for enzymes to use in metabolic reactions
1. A) a
higher diversity of cytochromes would likely be observed.
2. B)
cytochromes would be unnecessary for cells and quinones would be more
important.
3. C)
Q-cycle reactions would no longer be necessary for electron transport, but the
proton motive force would otherwise be unchanged.
4. D)
most metabolic pathways for both anabolism and catabolism would have to be
rewritten.
Answer: D
Bloom’s Taxonomy: 5-6: Evaluating/Creating
Chapter Section: 3.11
46) Which metabolic strategy does NOT invoke the proton motive
force for energy conservation?
1. A)
aerobic catabolism
2. B)
fermentation
3. C)
chemoorganotrophy
4. D)
photoautrophy
Answer: B
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.12
3.2 True/False Questions
1) ATP-binding cassette transport systems have high substrate
affinity and thus help microorganisms survive in low nutrient environments.
Answer: TRUE
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.2
2) A bacterial isolate that grows better on a nutrient agar
plate supplemented with amino acids but still grows in a nutrient agar plate
lacking amino acids suggests amino acids are trace nutrients for the isolate.
Answer: FALSE
Bloom’s Taxonomy: 5-6: Evaluating/Creating
Chapter Section: 3.1
3) Regeneration of oxaloacetate is essential for the citric acid
cycle to be cyclical.
Answer: TRUE
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.9
4) Depending on the particular metabolism of a bacterium,
electron transport can be used to energize and rotate ATP synthase.
Answer: FALSE
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.11
5) Each amino acid made during protein biosynthesis first
requires a separate biosynthetic pathway to be invoked by a cell.
Answer: FALSE
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.14
6) The terminating step of moving electrons onto oxygen releases
additional ATP during aerobic metabolism not made during anaerobic growth.
Answer: FALSE
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.11
7) Nitrogenases not only reduce N2 but also can act on acetylene
(C2H2).
Answer: TRUE
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.1
8) Due to the number of phosphate groups, ATP has approximately
three times more energy stored than AMP, and ADP has approximately two-thirds
the energy stored of ATP.
Answer: FALSE
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.7
9) In a given chemical reaction, if the free energy of formation
is known for all of the reactants and each of the products, the change in free
energy can be calculated for the reaction.
Answer: TRUE
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.4
10) Free-energy calculations are dependent on the rates of the
reactions.
Answer: FALSE
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.4
11) With respect to nitrogen utilization, relatively few
bacteria can use NH3 whereas many more can make use of N2.
Answer: FALSE
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.14
12) The proton motive force is most often generated by splitting
of H2.
Answer: FALSE
Bloom’s Taxonomy: 5-6: Evaluating/Creating
Chapter Section: 3.11
13) Biosynthesis of glucose can occur by compounds other than
sugars via gluconeogenesis.
Answer: TRUE
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.13
14) If a substance is reduced, it gains electrons.
Answer: TRUE
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.6
15) Molybdenum is a cofactor for nitrogenase, which means every
nitrogen-fixing microorganisms will not be able to fix nitrogen without Mo.
Answer: TRUE
Bloom’s Taxonomy: 3-4: Applying/Analyzing
Chapter Section: 3.1
16) Magnesium is not considered a growth factor for
microorganisms, because growth factors are always organic compounds.
Answer: TRUE
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.1
17) Cells require iron supplemented in their growth medium as a
trace metal, because it is consumed by quinones during electron transport for
ATP production.
Answer: FALSE
Bloom’s Taxonomy: 5-6: Evaluating/Creating
Chapter Section: 3.10
18) Varied coenzyme availability increases the diversity of
enzymatic reactions in both biosynthetic and catabolic pathways possible in a
cell.
Answer: TRUE
Bloom’s Taxonomy: 5-6: Evaluating/Creating
Chapter Section: 3.5
19) The energy released from the hydrolysis of coenzyme A is
conserved in the synthesis of ATP.
Answer: TRUE
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.7
20) In substrate-level phosphorylation, ATP storage is depleted
during the steps in catabolism of the fermentable compounds.
Answer: FALSE
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.8
21) Catabolic pathways are essential for microorganisms to
obtain energy, because biosynthetic reactions for cellular growth generally
require energy input.
Answer: TRUE
Bloom’s Taxonomy: 5-6: Evaluating/Creating
Chapter Section: 3.13
22) In electron transport systems, the electron carriers are
membrane associated.
Answer: TRUE
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.11
23) Heme prosthetic groups are involved in electron transfer
with quinones.
Answer: FALSE
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.5
24) During the electron transport process, protons and electrons
become physically separated in the cell membrane.
Answer: TRUE
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.10
25) Many defined growth media that support microbial growth lack
malonate, which is an important precursor for biosynthesis of lipid membranes.
Based on this, we can infer cells also must have a metabolic pathway to
generate malonate from other compounds.
Answer: TRUE
Bloom’s Taxonomy: 5-6: Evaluating/Creating
Chapter Section: 3.15
26) The net result of electron transport is the generation of a pH
gradient and an electrochemical potential across the membrane.
Answer: TRUE
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.11
27) A bacterium that lacks an arginine biosynthetic pathway
would still be able to make proteins with arginine and grow only if arginine is
supplemented into the growth medium.
Answer: TRUE
Bloom’s Taxonomy: 3-4: Applying/Analyzing
Chapter Section: 3.14
3.3 Essay Questions
1) Why is energy required for nutrient transport? Give an example
of a system that transports nutrients and describe what source of energy is
used to move the nutrients into the cell.
Answer: Energy is required for nutrient transport because
nutrient concentration outside of the cell is lower than the nutrient concentrations
inside the cell, thus nutrient transport moves solutes against a concentration
gradient and requires energy. There are three examples in the text. The student
could describe any one of them. They are (i) Simple transporter such as lac
permease. Each nutrient molecule is cotransported into the cell with a H+ ion,
thus the proton motive force provides the energy to transport nutrients. (ii)
Group translocation such as sugar phosphotransferases. Each nutrient molecule
is modified during the transport process. The modification, in this case,
phosphorylation, releases energy, thus the energy source is an energy-rich
compound such as phosphoenol pyruvate or some other phosphorylated compound.
(iii) ABC transporters. In this example specific binding proteins bind to
nutrient molecules with high affinity. Movement of the nutrient into the cell
is coupled to ATP hydrolysis, thus ATP is the source of energy for transporting
nutrients.
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.2
2) Explain the differences between symporters, and antiporters.
Answer: Answers should highlight differences in transport
direction and energy input.
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.2
3) Compare and contrast defined media and complex media. Use
specific examples in your answer.
Answer: Defined media are prepared by adding individual
“pure” chemicals in known quantities. In this way, the medium itself can be
explicitly defined. For example, 5 mM NaCl, 3 mM KH2PO4, 1.5 mM NH4Cl, 2.5%
glucose, and 3% acetate is a defined medium, because each ingredient added is
at a known concentration and the chemicals present are known. Complex media
needs only to contain one undefined product to be considered complex or
undefined. An example of an undefined medium is 5 mM NaCl, 2.5% tryptone and
2.5% yeast extract, because both tryptone and yeast extract are not individual
chemical structures but instead contain an assortment of compounds at unknown
(imprecise) quantities.
Bloom’s Taxonomy: 3-4: Applying/Analyzing
Chapter Section: 3.1
4) Categorize the circumstances under which the same substance
(molecule) can be either an electron donor or an electron acceptor.
Answer: Answers should explain that not all molecules are
strictly one or the other, and each molecule must be compared to the other in a
pair to determine which is the electron acceptor and which is an electron
donor.
Bloom’s Taxonomy: 3-4: Applying/Analyzing
Chapter Section: 3.6
5) Contrast fermentation and respiration in terms of electron
donor, electron acceptor, type of ATP production, and relative number of ATP
produced.
Answer: Respiration should be distinguished as using
separate electron donors and acceptors (such as organic carbon as the electron
donor and oxygen as the electron acceptor), while fermentation splits organic
molecules in order to oxidize one part of the molecule and reduce the other
part in order to regenerate NAD+. Fermentation uses substrate level
phosphorylation to generate relatively few ATP, while respiration uses
oxidative phosphorylation to generate more ATP.
Bloom’s Taxonomy: 3-4: Applying/Analyzing
Chapter Section: 3.8
6) Summarize the roles the proton motive force has in microbial
metabolism.
Answer: The proton motive force uses an energized cell
membrane for ATP synthesis via ATPase, transporting some ions and molecules
into and out of the cell, and flagellar rotation.
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.11
7) Discuss why energy yield in an organism undergoing anaerobic
respiration is less than that of an organism undergoing aerobic respiration.
Answer: One possible explanation could point to the
substrate-level phosphorylation process itself as being less energy yielding
than (aerobic) oxidative phosphorylation. Another reason is the fate of
pyruvate itself, where fermentation is unable to take it through the higher
energy yielding process, which requires O2 as a terminal electron acceptor.
Other answers could discuss the E0ʹ being greatest with the O2/H2O redox couple
in aerobic metabolism compared to anaerobic redox couples.
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.12
8) Explain the biosynthetic and bioenergetic roles of the citric
acid cycle.
Answer: Some of the molecules generated during the citric
acid cycle, such as alpha-ketoglutarate, oxalacetate, and succinyl-CoA, can
serve as precursors for the biosynthesis of critical cellular components such
as amino acids, chlorophyll, and cytochromes. The bioenergetic component of the
cycle should be described in the context of FADH2 and NADH electron donors
storing energy potential, usable in electron transport where O2 is reduced to
water.
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.8
9) In an aquatic microbial community where a photoautotroph,
chemoorganoheterotroph, and nitrogen fixing bacterium are present, predict an
environmental perturbation that would cause only one to be outcompeted by the
other two groups and explain how each group would respond.
Answer: Answers will vary but should highlight a unique
feature of one of the groups such as: photoautotrophs are sensitive to photon
(light) availability, chemoorganoheterotrophs require organic molecules for
carbon, and nitrogen fixing bacteria use N2 gas.
Bloom’s Taxonomy: 5-6: Evaluating/Creating
Chapter Section: 3.3
10) Differentiate between exergonic and endergonic in terms of
free-energy calculations.
Answer: A positive change in free energy (ΔG0ʹ) means the reaction
needs energy input to occur (called endergonic), whereas a negative ΔG0ʹ needs
no energy input and actually releases excess energy (called exergonic).
Bloom’s Taxonomy: 3-4: Applying/Analyzing
Chapter Section: 3.4
11) Explain what an enzyme must accomplish to catalyze a
specific reaction.
Answer: Answers will vary, but the focus of the answer
should be on overcoming the required activation energy.
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.5
12) A beer-making microbiologist noticed that no matter how long
the brewing process went, 3% alcohol was the maximum produced. Hypothesize what
is causing this low level of alcohol in reference to the brewer’s recipe and
recommend how a higher alcohol yield could be achieved. Ethanol is toxic at
high concentrations, but ignore this factor to focus on microbial metabolism.
Answer: Answers will vary but one explanation is a low
substrate concentration resulted in low fermentation to produce ethanol.
Providing more carbohydrates such as glucose to the yeast in the recipe for the
same growth period would increase fermentation activity and ethanol production.
Another explanation is that there may be too much oxygen introduced during the
brewing process, which would result in the complete oxidation of glucose
instead of fermentation to ethanol. The brewer would need to take more
precautions to exclude oxygen during brewing.
Bloom’s Taxonomy: 5-6: Evaluating/Creating
Chapter Section: 3.8
13) Explain why the amount of energy released in a redox
reaction depends on the nature of both the electron donor and the electron
acceptor.
Answer: Answers should emphasize that energy does not come
from specific molecules but rather from the difference in reduction potential
between two molecules. For example, assigning arbitrary values and subtracting
them from one another by comparing two different electron acceptors to one
donor would indicate differences in energy for an electron acceptor. In a
similar way, this could also be shown to mathematically explain electron donors
having an equal role in determining ΔE0ʹ.
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 3.6
14) Consider a pizza dough made by vigorously mixing to form
gluten and evenly disperse the ingredients such as bakerʹs yeast (Saccharomyces cerevisiae).
Predict the metabolic differences yeast would have in a thinly flattened dough
and in a spherical dough ball.
Answer: A flattened dough would have higher surface area
and more oxygen exposure to support aerobic respiration of S. cerevisiae. The dough
ball on the other hand would initially have aerobic metabolism of S. cerevisiae due to
the mixing. Once oxygen is depleted from respiration the yeast would begin
anaerobic fermentation, especially in the center of the dough ball while the
surface of the dough ball could still support aerobic growth if not enclosed in
a container.
Bloom’s Taxonomy: 5-6: Evaluating/Creating
Chapter Section: 3.8
Brock Biology of Microorganisms, 15e (Madigan
et al.)
Chapter 4 Molecular Information Flow and Protein
Processing
4.1 Multiple Choice Questions
1) The functional unit of genetic information is the
1. A)
nucleotide.
2. B)
gene.
3. C)
chromosome.
4. D)
protein.
Answer: B
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 4.1
2) Which of the following statements is TRUE concerning mRNA?
1. A)
mRNA has a very short half-life.
2. B)
mRNA has complex secondary structure.
3. C)
mRNA is catalytic.
4. D)
mRNA is the product of translation.
Answer: A
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 4.6
3) DNA-binding proteins interact predominantly within which
portion of a double-stranded DNA helix?
1. A)
major groove
2. B)
minor groove
3. C) 3ʹ
end
4. D)
supercoil
Answer: A
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 4.1
4) AT-rich DNA will denature/melt
1. A) at
a higher temperature than GC-rich DNA.
2. B) at
a lower temperature than GC-rich DNA.
3. C)
usually at the same temperature as GC-rich DNA, with some minor variations.
4. D) in
accordance with the animal or plant from which it was taken.
Answer: B
Bloom’s Taxonomy: 5-6: Evaluating/Creating
Chapter Section: 4.1
5) Supercoiling is important for DNA structure, because
1. A) it
holds together the antiparallel strands of DNA in the double helix.
2. B) it
provides energy for transcription.
3. C) it
condenses the DNA so that it can fit inside the cell.
4. D) it
prevents RNA from pairing with DNA in the double helix.
Answer: C
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 4.1
6) Many pharmaceutical drugs specifically inhibit transcription
in Bacteria but
not Archaea or Eukarya. Why would
drugs that inhibit transcription only affect Bacteria and not Archaea even though
they are both prokaryotes?
1. A) Archaea and Eukarya have very
similar ribosomes that are different than bacterial ribosomes.
2. B) Bacteria lack a
nucleus.
3. C) Archaea lack
operons.
4. D) Archaea and Eukarya have very
similar RNA polymerases that are different than bacterial RNA polymerases.
Answer: D
Bloom’s Taxonomy: 3-4: Applying/Analyzing
Chapter Section: 4.6
7) How are plasmids different than chromosomes?
1. A)
Plasmids are always small, linear pieces of DNA.
2. B)
Plasmids are composed of single-stranded DNA.
3. C) Plasmids
contain genes that are NOT essential for cellular growth and replication.
4. D)
Plasmids carry unimportant genes that are of little significance for the
ecology and metabolism of an organism.
Answer: C
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 4.2
8) Genes that are encoded for polymerases, gyrases, ribosomal
proteins, and other proteins essential to replication, transcription, and
translation are present on
1. A)
chromosomes.
2. B)
plasmids.
3. C)
chromosomes and plasmids.
4. D)
neither chromosomes nor plasmids.
Answer: A
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 4.2
9) The precursor of each new nucleotide in a strand of DNA is a
1. A)
deoxynucleoside 5ʹ-diphosphate.
2. B)
deoxynucleoside 3ʹ-diphosphate.
3. C)
deoxynucleoside 5ʹ-triphosphate.
4. D)
deoxynucleoside 3ʹ-triphosphate.
Answer: C
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 4.3
10) DNA replication always proceeds in only one direction
because the ________ of the incoming nucleotide is attached to the free
________ of the growing DNA strand.
1. A)
5ʹ-phosphate / 3ʹ-hydroxyl
2. B)
3ʹ-phosphate / 5ʹ-hydroxyl
3. C)
5ʹ-deoxyribose / 3ʹ-base
4. D)
3ʹ-base / 5ʹ-deoxyribose
Answer: A
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 4.3
11) Which of the following is formed on the lagging strand
during DNA synthesis?
1. A)
DNA secondary structures
2. B)
Okazaki fragments
3. C)
RNA polymerase
4. D)
replisomes
Answer: B
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 4.3
12) The template for RNA polymerase is ________, and the new RNA
molecule is ________ to the template.
1. A) an
independent RNA segment / parallel and identical
2. B)
DNA / antiparallel and complementary
3. C) an
independent RNA segment / antiparallel and complementary
4. D)
DNA / parallel and identical
Answer: B
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 4.5
13) In the process of transcription, promoters are specific
sequences of ________ that are recognized by ________.
1. A)
DNA / DNA polymerase
2. B)
RNA / DNA polymerase
3. C)
DNA / sigma factors
4. D)
RNA / ribosomes
Answer: C
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 4.5
14) An example of correct nucleotide pairing is
1. A) T
and U.
2. B) G
and U.
3. C) A
and T.
4. D) C
and U.
Answer: C
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 4.5
15) Stop codons are also called ________ codons.
1. A)
nonsense
2. B)
release factor
3. C)
degeneracy
4. D) conversion
Answer: A
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 4.9
16) Transfer RNA (tRNA) molecules
1. A)
function to transfer ribonucleotides to RNA polymerase during transcription.
2. B)
function to transfer the correct amino acids to the ribosome during
translation.
3. C)
contain codons that bind to ribosomes during translation.
4. D)
are only present in the nucleus or eukaryotes.
Answer: B
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 4.8
17) tRNA is released from the ribosome at the ________ site.
1. A) P
2. B) A
3. C) R
4. D) E
Answer: D
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 4.9
18) Which statement is TRUE regarding protein synthesis?
1. A)
Ribosomal proteins catalyze peptide bond formation in the growing polypeptide
chain.
2. B)
The 23S rRNA catalyzes peptide bond formation in the growing polypeptide chain.
3. C)
Transfer RNAs catalyze peptide bond formation in the growing polypeptide chain.
4. D)
Messenger RNA catalyzes peptide bond formation in the growing polypeptide
chain.
Answer: B
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 4.9
19) The Tat system is involved in
1. A)
protein synthesis.
2. B)
transcriptional initiation.
3. C)
protein folding.
4. D)
protein secretion.
Answer: D
Bloom’s Taxonomy: 1-2: Remembering/Understanding
Chapter Section: 4.12
Comments
Post a Comment