A chemical reaction that has a negative �G0
a) is an endergonic reaction.
b) will require an input of energy.
c) is not a spontaneous reaction.
d) is an energy yielding reaction.
e) will absorb energy.
d) is an energy yielding reaction.
How do enzymes increase the rate of a biochemical reaction?
a) By lowering the activation energy.
b) By increasing the standard free energy.
c) By lowering the standard free energy.
d) By increasing the activation energy.
e) By lowering the reduction pote
a) By lowering the activation energy.
Which of these is an example of a coenzyme?
a) glucose
b) iron
c) NAD+
d) cytochrome c
e) a kinase
c) NAD+
Which of these is the most widely used form of energy in cell
processes?
a) glucose
b) NADH
c) pyruvate
d) ATP
e) citrate
d) ATP
The biochemical reaction, PEP + ADP �! Pyruvate + ATP, is an
example of which of these?
a) An oxidation/reduction reaction.
b) Oxidative phosphorylation.
c) Substrate-level phosphorylation.
d) An aldolase catalyzed reaction.
e) An electron transport react
c) Substrate-level phosphorylation.
How is the activity of an allosteric enzyme regulated?
a) By a coenzyme.
b) By covalent modification.
c) Through the binding of an effector molecule.
d) Through the binding of a competitive inhibitor.
e) By substrate binding.
c) Through the binding of an effector molecule.
Oxidative phosphorylation uses ALL of the following for energy
production EXCEPT:
a) electrons from NADH.
b) membrane-associated electron transport chain.
c) an ATP synthase.
d) phosphoenolpyruvate.
e) a proton motive force.
d) phosphoenolpyruvate.
When oxygen reacts with hydrogen gas, water is produced as the
product in this oxidation-reduction reaction. Hydrogen donates
electrons to oxygen in the reaction. Which statement below is true
about this reaction?
a) Oxygen is oxidized to water.
b) Oxygen
b) Oxygen is being reduced in the reaction.
The standard reduction potential (E0�) for ferredoxin (Fdox/Fdred)
is (-0.43 V). Based on this, which of these would you expect to be
true?
a) Oxidized ferredoxin to be a good electron donor.
b) Oxidized ferredoxin to be a good electron acceptor.
c) Reduc
c) Reduced ferredoxin to be a good electron donor.
What does a large positive �E0 indicate for a redox reaction?
a) It is endergonic.
b) It has a positive �G0 .
c) It will require an input of energy.
d) It is spontaneous.
e) It is energetically unfavorable.
d) It is spontaneous.
Which of these is TRUE for a chemoorganoheterotroph?
a) Uses inorganic carbon as an energy source and organic carbon as a
carbon source.
b) Uses inorganic carbon as an electron source and organic carbon as a
carbon source.
c) Uses organic carbon as an ele
d) Uses organic carbon as an electron source and a carbon source.
Which of these is TRUE for a chemolithoautotroph?
a) inorganic molecules as energy sources and inorganic carbon as a
carbon source.
b) organic molecules as electron sources and inorganic carbon as a
carbon source.
c) organic molecules as energy sources an
a) inorganic molecules as energy sources and inorganic carbon as a
carbon source.
Cyanobacteria carry out oxygenic photosynthesis producing oxygen
as a byproduct from the oxidation of water, which serves as the
electron donor for the light-dependent reactions. How would
cyanobacteria be classified?
a) chemoorganoautotroph
b) chemoorgan
e) photolithoautotroph
How many NET molecules of ATP are produced during the Embden-
Meyerhof pathway of glycolysis for every molecule of glucose that is
converted into two molecules of pyruvate?
a) one
b) two
c) four
d) six
e) ten
b) two
What are the NET products of the Embden-Meyerhof pathway, when
operating in the catabolic direction?
a) Two pyruvate, two ATP, and two NADH.
b) Two pyruvate, four ATP, and four NADH.
c) Two CO2, four pyruvate, two ATP, and four NADH.
d) Two CO2, two pyruv
a) Two pyruvate, two ATP, and two NADH.
Which of these are important products of the pentose phosphate
pathway that are used in biosynthesis?
a) pyruvate, ribose-5-phosphate, and NADPH
b) NADPH, ribose-5-phosphate, and erythrose-4-phosphate
c) pyruvate, citrate, and erythrose-4-phosphate
d) pyr
b) NADPH, ribose-5-phosphate, and erythrose-4-phosphate
Microorganisms that rely solely on fermentation reactions for
energy production make ATP primarily by this method.
a) oxidative phosphorylation
b) electron transport phosphorylation
c) membrane bound ATPase
d) substrate-level phosphorylation
e) the oxidat
d) substrate-level phosphorylation
Fermentation can most accurately be described by which of these?
a) The reoxidation of NADH by an electron transport chain.
b) A process that occurs in the absence of oxygen.
c) An energy producing process found in all anaerobes.
d) The direct reoxidation
d) The direct reoxidation of NADH by an internal organic molecule.
Lactic acid is a common fermentation product. It is produced when
___________ is reduced by electrons received from NADH.
a) ethanol
b) glucose
c) pyruvate
d) acetyl-CoA
e) 3-phosphoglyceraldehyde
c) pyruvate
The products of yeast fermentation, when including the Embden-
Meyerhof pathway of glycolysis for one molecule of glucose, are two
ethano molecules as well as these others.
a) two ATP and two NADH
b) two ATP, two NADH, and two CO2
c) four ATP and two NADH
d) two ATP and two CO2
When does feedback inhibition of an enzyme occur?
a) If an end product of the pathway binds to the allosteric site of
the enzyme.
b) If a competitive inhibitor binds to the active site of the enzyme.
c) If the coenzyme fails to bind to the active site of
a) If an end product of the pathway binds to the allosteric site of
the enzyme.
The pyruvate dehydrogenase reaction catalyzes the oxidation and
decarboxylation of pyruvate into which of these products?
a) an acetyl group + CO2.
b) lactic acid
c) citrate
d) ethanol + CO2
e) acetic acid and CO2
a) an acetyl group + CO2.
Which of these sets are products of the TCA (Krebs) Cycle?
a) NADH, ATP, CO2, and oxaloacetate
b) NADH, FADH2, and ATP
c) NADH, FADH2, and oxaloacetate
d) NADH, FADH2, CO2, and ATP
e) NADH, FADH2, CO2, and oxaloacetate
d) NADH, FADH2, CO2, and ATP
Which of these is NOT an electron carrier used in the electron
transport system?
a) flavoproteins
b) iron-sulfur proteins
c) ATPase
d) quinones
e) cytochromes
c) ATPase
Which statement is TRUE with respect to the electron transport
system?
a) The electron transport system accepts electrons directly from
glucose.
b) In bacteria, the electron transport system is located in the
cytoplasm.
c) A proton motive force is generat
c) A proton motive force is generated as electrons move through the
system to a terminal acceptor.
Which of these occurs in anaerobic respiration, but not in aerobic
respiration?
a) A fermentation product is produced.
b) The terminal cytochrome oxidase is replaced by a cytochrome
reductase.
c) Glucose is only partially oxidized to CO2.
d) NADH dehydrog
b) The terminal cytochrome oxidase is replaced by a cytochrome
reductase.
Which of the following would NOT be appropriate as a terminal
electron acceptor during anaerobic respiration?
a) nitrate (NO3-)
b) sulfate (SO42-)
c) sulfur (S0)
d) ferric iron (Fe3+)
e) hydrogen sulfide (H2S)
e) hydrogen sulfide (H2S)
What can the proton motive force generated by the electron
transport system be used for?
a) NADH oxidation, ATP synthesis, and flagella rotation
b) NADH oxidation, ATP synthesis, and nutrient transport
c) ATP synthesis, flagella rotation, and nutrient tra
c) ATP synthesis, flagella rotation, and nutrient transport
How is ATP is primarily produced in chemolithotrophs?
a) Fermentation reactions.
b) Anaerobic respiration.
c) Electrons moving through an electron transport system to generate a
proton motive force.
d) Glycolysis and TCA cycle reactions.
e) Using reduced
c) Electrons moving through an electron transport system to generate a
proton motive force.
Term for the primary pathway for fatty acid oxidation?
a) Calvin cycle
b) pentose phosphate pathway
c) Parnas pathway
d) ?-oxidation pathway
e) reductive TCA pathway
d) ?-oxidation pathway
Enzymes that break down proteins into individual amino acids.
a) amylases
b) proteases
c) reductases
d) dehydrogenases
e) lipases
b) proteases
The product(s) of the light reactions of photosynthesis.
a) glucose and ATP
b) glucoseonly
c) ATPonly
d) glucose and NADPH
e) ATP and NADPH
e) ATP and NADPH
What is the chromophore of the chlorophyll molecule composed of?
a) A carotenoid molecule with an atom of iron in the center.
b) A porphyrin molecule with an atom of iron in the center.
c) A phycoerythrin with an atom of iron in the center.
d) A porphyrin
d) A porphyrin molecule with an atom of magnesium in the center.
Chlorophyll a maximally absorbs light energy at what
frequency(ies)?
a) 430 nm and 662 nm
b) 550 nm
c) 750 nm and 850 nm
d) 900 nm
e) 800 nm and 950 nm
a) 430 nm and 662 nm
Which organisms contain bacteriochlorophyll?
a) cyanobacteria
b) cyanobacteria and purple non-sulfur bacteria
c) cyanobacteria and green sulfur bacteria
d) cyanobacteria, purple sulfur bacteria, and green sulfur bacteria
e) purple sulfur, purple non-sulfu
e) purple sulfur, purple non-sulfur, and green sulfur bacteria
Where is the reaction center of photosystems located?
a) In the cytoplasm.
b) In the periplasmic space.
c) Within a biological membrane.
d) Either in the cytoplasm or within a membrane.
e) Within the cell wall.
c) Within a biological membrane.
Some anoxygenic photosynthetic bacteria are able to use _______ as
an electron source.
a) light
b) CO2
c) H2S
d) H2O
e) nitrate
c) H2S
How is ATP generated during the light-dependent reactions of
photosynthesis?
a) Substrate-level phosphorylation.
b) A proton motive force driven ATP synthase.
c) Electron driven NADPH synthase.
d) Carbon dioxide fixation.
e) Chlorophyll a.
b) A proton motive force driven ATP synthase.
The purple sulfur bacteria produce reducing power during the light
reactions of photosynthesis by what process?
a) cyclic photophosphorylation
b) the Calvin cycle
c) reverse electron flow
d) the reverse TCA cycle
e) the Parnas pathway
c) reverse electron flow
Cyanobacteria use _______ as an electron source for the reduction
of NADP+.
a) sulfur
b) glucose
c) water
d) carbon dioxide
e) nitrate
c) water
How would the �dark reactions� of photosynthesis best be
described?
a) energy generating reactions
b) carbon dioxide fixing reactions
c) glycolytic reactions
d) reducing power generating reactions
e) part of photosystem II
b) carbon dioxide fixing reactions
The key carbon dioxide fixation reaction in the Calvin Cycle is
carried out by which enzyme?
a) ribulose 1,5-bisphosphate carboxylase
b) ribulose 1,5-bisphosphate kinase
c) ribose 1,5-bisphosphate carboxylase
d) ribose 1,5-bisphosphate kinase
e) ribose 1,
a) ribulose 1,5-bisphosphate carboxylase
For what purpose is the reductive TCA cycle used by the green
sulfur bacteria?
a) carbon dioxide fixation
b) generation of reducing power
c) glucose breakdown
d) energy generation
e) respiration
a) carbon dioxide fixation
Nitrogen fixation is the reduction of _______ to ammonia for cell
use.
a) nitrate
b) nitrite
c) hydroxylamine
d) dinitrogen
e) nitric oxide
d) dinitrogen
How many ATP molecules is required to �fix� a molecule of
nitrogen?
a) one
b) two
c) four
d) eight
e) sixteen
e) sixteen
Which nitrogen species is most readily incorporated into an
organic molecule in the cell?
a) dinitrogen
b) nitrate
c) nitrite
d) ammonia
e) nitric oxide
d) ammonia
Which amino acids are the primary nitrogen donors for biosynthetic
reactions in the cell?
a) glycine and glutamate
b) glycine and serine
c) glutamine and glutamate
d) glutamine and serine
e) serine and glutamate
c) glutamine and glutamate
What is dissimulative nitrate reduction?
a) The production of nitrate from ammonia.
b) The incorporation of nitrate into cellular material.
c) Anaerobic reduction of nitrate.
d) Nitrogen fixation.
e) The production of nitrate from nitrite.
c) Anaerobic reduction of nitrate.
What is denitrification?
a) The reduction of nitrate to dinitrogen.
b) The production of nitrate from ammonia.
c) The reduction of dinitrogen to nitrate.
d) The assimilation of nitrate by the cell.
e) The assimilation of ammonia by the cell.
a) The reduction of nitrate to dinitrogen.
Which of these best describes assimilatory sulfatereduction?
a) The reduction of sulfate to elemental sulfur.
b) The reduction of sulfate for incorporation into cellular material.
c) The reduction of sulfate to sulfide for excretion by the cell.
d) A type
b) The reduction of sulfate for incorporation into cellular material.
The biosynthesis of amino acids requires starting intermediates
from which of these pathways?
a) glycolysisonly
b) the TCA cycleonly
c) glycolysis and TCA cycle
d) the pentose phosphate pathway and glycolysis
e) glycolysis, TCA cycle, and the pentose phos
e) glycolysis, TCA cycle, and the pentose phosphate pathway
The most common lipids in the cell are synthesized from
___________ and ____________.
a) fatty acids and sterol
b) fatty acids and glycerol
c) fatty acids and hopanoids
d) hopanoids and sterols
e) glycerol and hopanoids
b) fatty acids and glycerol
Metabolic processes in the cell that yield energy are called
____________
__________exergonic__
Enzymes increase the rate of a biochemical reaction by lowering
the _________ _________ of the reaction.
activation energy
ATP that is produce directly from a biochemical reaction in the
cell as the result of a phosphate transfer to ADP is called
____________ phosphorylation.
substrate-level
Organism that use light as energy sources are called
_____________.
phototrophs or phototroph
Organism that use inorganic molecules as electron sources are
called ______________.
lithotrophs or lithotroph
The pentose phosphate pathway is important for producing the
intermediate ribose-5-phosphate for the synthesis of
__________________.
nucleotides
The use of an exogenous terminal electron acceptor other than
oxygen is called __________ __________.
anaerobic respiration
During the respiratory process, as electrons are passed through
the electron transport chain, a ________ ________ force is generated
across a biological membrane to drive the synthesis of ATP by a
membrane associated ATP synthase.
Proton motive
The photosynthetic membranes in cyanobacteria are called
__________ membranes.
thylakoid
The type of photosynthesis that does NOT produce oxygen is called
___________ photosynthesis.
anoxygenic
The pathway of carbon dioxide fixation used by cyanobacteria is
called the ___________ __________.
calvin cycle
The reduction of dinitrogen to ammonia for assimilation is called
nitrogen ________.
fixation
The reduction of nitrate to a gaseous form of nitrogen, such as
dinitrogen, is called __________.
denitrification