Microbiology Quiz Chapter 5 part 2 – Flashcards
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which of the following statements are TRUE?
1-electron carriers are located at ribosomes
2-ATP is a common intermediate between catabolic and anabolic pathways
3-ATP is used for the long-term storage of energy and so is often found in storage granules
4-anaerobic organisms are capable of generating ATP via respiration
5-ATP can be generated by the flow of protons across protein channels
a) 2,3,5
b) 2,4,5
c) 1,2,3
d) 1,3,4
e) all of the statements are true
answer
b) 2,4,5
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which of the following is true of anabolic reactions?
a) anabolic and catabolic reactions both build complex organic molecules from simpler ones; however, anabolic reactions use ATP, whereas catabolic reactions transfer energy to create ATP
b) anabolic reactions use ATP and small substrates as building blocks to synthesize larger molecules
c) anabolic reactions proudces energy, which is used to convert ADP to ATP
d) anabolic reactions break down complex organic compounds into simpler ones.
answer
b) anabolic reactions used ATP and small substrates as building blocks to synthesize larger molecules.
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In general, ATP is generated in catabolic pathways and expended in anabolic pathways.
true or false
answer
true
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in metabolism, energy that is not used
a) is given off as heat
b) is used to build up large compounds from smaller ones
c) is used to break down larger molecules into smaller ones
d) is stored in the form of ATP
answer
is given off as heat
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the reactions involved in producing larger compounds from smaller compounds is called
a) metabolism
b) catabolism
c) anabolism
answer
anabolism
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where does the energy required for anabolic reactions come from?
a) catabolic reactions
b) unused energy from metabolism
c) heat
answer
catabolic reactions
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the use of amino acids to make proteins
a) is an example of anabolism
b) is an example of catabolism
c) is a completely efficient reaction
d) involves the productions of ATP
answer
is an example of anabolism
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A new antibiotic is produced that inhibits the synthesis of acetyl-CoA and the electron transport chain in bacteria. For each glucose molecule that is metabolized, how many fewer ATP molecules will be produced?
a) 4
b) 38
c) 2
d) 36
e) 34
answer
36
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what is the fate of pyruvic acid in an organism that uses aerobic respirations?
a) it is reduced to lactic acid
b) it is oxidized in the electron transport chain
c) it reacts with oxaloacetate to form citrate
d) it is converted into acetyl CoA
e) it is catabolized in glycolysis
answer
it is converted into acetyl CoA
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Which of the following statements regarding the glycolysis pathway is FALSE?
a) two NADH molecules are generated
b) two pyruvate molecules are generated
c) two molucules of water are generated
d) four ATP molecules are generated via substrate-level phosphorylation
e) one molecules of ATP is expended
answer
one molecule of ATP is expended
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in cellular respiration of glucose, what are the three principal stages?
a) chemiosmosis, photophosphorylation, and reduction
b) fermentation, Kerbs cycle, and electron transport chain
c) Calvin-Benson cycle, electron transport chain, and glycolysis
d) glycolysis, Kerbs cycle, and the electron transport chain
answer
glycolysis, Kerbs cycle, and the electron transport chain
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why does lack of oxygen result in the halt of ATP synthesis?
a) oxygen prevents uncoupling of the electron transport chain
b) the chain shuts down and can no longer pump hydrogen ions across the membrane, and the proton gradient cannot be maintained
c) it causes one of the cytochromes in the electron transport chain to be permanently stuck in the reduced state.
answer
the chain shuts down and can no longer pump hydrogen ions across the membrane, and the proton gradient cannot be maintained
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why might some cells uncouple the electron transport chain?
a) uncoupling proteins offset the effect of cyanide
b) too much ATP is bad for the cell
c) a cell does not require ATP
d) cells can use the energy from the proton gradient for function other than producing ATP, such as heat generation
answer
cell can use the energy from the proton gradient for functions other than producing ATP, such as heat generation
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how does cyanide poisoning result in the decrease of ATP production?
a) cyanide permanently oxidized cytochrome a3, preventing other componets to change into the reduced state. This causes the proton gradient to break down, stopping ATP syntesis
b) Cyanide uncouples the proton gradient from the process of ATP synthesis
c)Cyanide permanently binds to oxygen, preventing its use as the final electron acceptor
d)Cyanide permanently reduces cytochrome a3, preventing other components to change into the oxidized state. This causes the proton gradient to break down, stopping ATP synthesis.
answer
Cyanide permanently reduces cytochrome a3, preventing other components to change into the oxidized state. This causes the proton gradient to break down, stopping ATP synthesis.
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which of the following situations does not result in a breakdown of the proton gradient?
a) oxygen deprivation
b) cyanide poisoning
c) uncoupling proteins
answer
uncoupling proteins
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where would you expect to find electron transport chains in a prokaryote?
a) along the plasma membrane
b) along the inner mitochondrial membrane
c) free-floating in the cytoplasm
d) along the cell wall
e) along the outer mitochondrial membrane
answer
along the plasma membrane
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which compounds provide electrons to the system?
a) oxygen
b) NADH
c) Water
d) NADH and FADH2
e) FADH2
answer
NADH and FADH2
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what does oxygen get reduced to the end of the electron transport chain?
a) protons
b) electrons
c) water
d) ATP
e) NADH
answer
water
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what does the electron transport chain do to the concentration of hydrogen ions (protons)?
a) the concentration of protons is lower outside the membrane than inside
b) the concentration of protons is higher outside the membrane than inside
c) the concentration of protons inside the membrane is equal to the concentration outside of the membrane.
answer
the concentration of protons is higher outside the membrane than inside
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the process of generating ATP using a proton gradient is referred to as
a) the electron transport chain
b) water damming
c) chemiosmosis
answer
chemiosmosis
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why does FADH2 yield less ATP than NADH?
a) FADH2 electrons enter the electron transport chain at a lower energy level.
b) FADH2 electrons ultimately do not go to oxygen.
c) FADH2 binds directly to the ATP synthase enzyme.
d) Electrons from FADH2 cannot pump hydrogen ions out of the cell.
answer
FADH2 electrons enter the electron transport chain at a lower energy level.
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Which of the following can be used as a final electron acceptor for aerobic respiration?
a) Molecular oxygen
b) Sulfate ion
c) Nitrate ion, sulfate ion and carbonate ion can all be used as a final electron acceptor.
d) Carbonate ion
e) Nitrate ion
answer
molecular oxygen
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What is one difference between ubiquinones and cytochromes?
a) Ubiquinones can only be reduced; cytochromes can only be oxidized.
b) Ubiquinones cannot carry electrons; cytochromes can.
c) Ubiquinones can only be oxidized; cytochromes can only be reduced.
d) Ubiquinones are not made of protein; cytochromes are.
answer
protons move from outside the membrane to inside the membrane
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Iron is considered an essential element for many bacteria. Based on the animation, how would lack of iron affect energy production of a bacterium?
a) Lack of iron would mean that most of the oxygen could be reduced to form water, improving energy yields.
b) Lack of iron would mean lack of heme, and thus lower amounts of functioning cytochrome proteins. This would mean lower energy yields.
c) Lack of iron would not have any affect on this system.
answer
Lack of iron would mean lack of heme, and thus lower amounts of functioning cytochrome proteins. This would mean lower energy yields.
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why is ATP required for glycolysis?
a) ATP makes it easier to break apart glucose into two three-carbon molecules.
b) ATP is used to reduce NAD+ to NADH.
c) ATP is used to convert DHAP into G3P.
d) ATP is used to convert PEP into pyruvic acid.
answer
ATP makes it easier to break apart glucose into two three-carbon molecules.
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Glycolysis literally means
a) energy producing
b) sugar splitting
c) Embden-Meyerhof
d) sugar producing
answer
sugar splitting
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How many net ATPs can be made from one molecule of glucose in glycolysis?
a) six
b) two
c) one
d) four
answer
two
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what carbon molecule remains at the end of glycolysis?
a) glucose
b) dihydroxyacetone phosphate (DHAP)
c) glyceraldehyde 3-phosphate (G3P)
d) Pyruvic Acid
answer
Pyruvic acid
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Which of the following statements about glycolysis is true?
a) Glycolysis is also called the Embden-Meyerhof pathway.
b) Glycolysis produces glucose.
c) All cells perform glycolysis.
d) Glycolysis is the main source of NADH in the cell.
answer
Glycolysis is also called the Embden-Meyerhof pathway.
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Glycolysis produces energy in which form?
a) NADH, ATP, and pyruvic acid
b) Pyruvic acid
c) ATP
d) NADH and ATP
e) NADH
answer
NADH and ATP
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Which step is the step for which glycolysis is named?
a) First
b) Second
c) Third
d) Fourth
e) Fifth
f) Sixth
answer
fourth
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What is meant by substrate-level phosphorylation?
a) Production of ATP by transferring phosphates directly from metabolic products to ADP
b) Production of ATP using energy from a proton gradient
c) Reduction of NAD+ to NADH
d) Splitting of glucose into two pyruvic acid molecules
answer
Production of ATP by transferring phosphates directly from metabolic products to ADP
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What is the driving force of energy production in steps 6 and 7?
a) The reduction of three-carbon compounds
b) The reduction of NAD+ to NADH
c) The oxidation of three-carbon compounds
d) The energy potential of a proton gradient
answer
The oxidation of three-carbon compounds
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what is the net production of ATP in glycolysis?
a) four ATP
b) eight ATP
c) two ATP
d) six ATP
answer
two ATP
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what occurs at the bridge step?
a) the production of GTP
b) Decarboxylation of pyruvic acid
c) the formation of succinyl CoA
d) the formation of oxaloacetate
answer
Decarboxylation of pyruvic acid
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how many electron carriers are reduced in the Kerbs cycle only?
a) three
b) five
c) four
d) six
answer
four
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what is the function of GTP?
a) an electrons carrier
b) an oxidizer to produce CO2
c) an energy carrier
d) a scaffolding for carbon atms
answer
an energy carrier
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what is the fate of metabolites during respiration?
a) They are oxidized completely to carbon dioxide and water.
b) They are oxidized completely to form pyruvic acid.
c) They are reduced to from NADH and FADH2.
d) They are rearranged to form GTP.
answer
They are oxidized completely to carbon dioxide and water
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which of the following is needed as a reactant for the first steps of the citric acid cycle?
a) Citric acid
b) Succinyl CoA
c) Malic acid
d) Oxaloacetic acid
answer
oxaloacetic acid
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where does the energy come from to power the formation of GTP?
a) NADH
b) succinyl CoA
c) ATP
d) Water
answer
Succinyl CoA
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which step involves the release of carbon dioxide?
a) the first and eighth steps
b) the third and fourth steps
c) the second step
d) the seventh step
answer
the third and fourth steps
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how many molecules of ATP can be generated from one molecule of NADH?
a) one
b) two
c) four
d) three
answer
three
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which step(s) of the Kerbs cycle does (do) not produce any usable energy?
a) the fifth step
b) the second and seventh steps
c) the first and eighth steps
d) the sixth step
e) the third step
answer
the second and seventh steps