Unit 2 (Week 6 Assignment Questions) Flashcards
Which of the following pathways occurs in the cytosol?
glycolysis
breakdown of pyruvate to an acetyl group
citric acid cycle
oxidative phosphorylation
all of the above
A
The net products of glycolysis are
6 CO2, 4 ATP, and 2 NADH.
2 pyruvate, 2 ATP, and 2 NADH.
2 pyruvate, 4 ATP, and 2 NADH.
2 pyruvate, 2 GTP, and 2 CO2.
2 CO2, 2 ATP, and glucose.
B
During glycolysis, ATP is produced by
oxidative phosphorylation.
substrate-level phosphorylation.
redox reactions.
all of the above.
both a and b.
B
Which organic molecule supplies a two-carbon group to start the citric acid cycle?
ATP
NADH
acetyl CoA
oxaloacetate
both a and b
C
The ability to diagnose tumors using [18F]-fluorodeoxyglucose (FDG) is based on the phenomenon that most types of cancer cells exhibit higher levels of
glycolysis.
pyruvate breakdown.
citric acid metabolism.
oxidative phosphorylation.
all of the above.
A
In the experiment of Racker and Stoeckenius, bacteriorhodopsin was oriented in such a way that it pumped H+ into a vesicle. Each vesicle actually contained many molecules of bacteriorhodopsin. How would the results of the experiment have been affected if 50% of the bacteriorhodopsin molecules pumped H+ into the vesicle and 50% pumped H+ out of the vesicles?
The same amount of ATP would be made in the presence of light, and no ATP would be made in the dark.
More ATP would be made in the presence of light, and no ATP would be made in the dark.
No ATP would be made in the presence of light, and no ATP would be made in the dark.
No ATP would be made in the presence of light, but some ATP would be made in the dark.
Some ATP would be made in the presence of light, and some ATP would be made in the dark.
C
Certain drugs, which are called ionophores, cause the mitochondrial membrane to be highly permeable to H+. How would such drugs affect oxidative phosphorylation?
Movement of electrons down the ETC would be inhibited.
ATP synthesis would be inhibited.
ATP synthesis would be unaffected.
ATP synthesis would be stimulated.
Both a and b would occur.
B
The source of energy that directly drives the synthesis of ATP during oxidative phosphorylation is the
oxidation of NADH.
oxidation of glucose.
oxidation of pyruvate.
H+ electrochemical gradient.
reduction of O2.
D
Compared with oxidative phosphorylation in mitochondria, anaerobic respiration in bacteria differs in that
more ATP is made.
ATP is made only via substrate-level phosphorylation.
O2 is converted to H2O2 rather than H2O.
something other than O2 acts as a final electron acceptor of the ETC.
both b and d occur.
D
When conditions in a muscle become anaerobic during strenuous exercise, why is it necessary to convert pyruvate to lactate?
to decrease NAD+ and increase NADH
to decrease NADH and increase NAD+
to increase NADH and increase NAD+
to decrease NADH and decrease NAD+
to keep oxidative phosphorylation running
B
The electron transport chain is so named because electrons are transported from one component to another. Describe the purpose of the ETC.
The purpose of the electron transport chain is to pump H+ across the inner mitochondrial membrane to establish an H+ electrochemical gradient. When H+ flow back across the membrane through ATP synthase, ATP is synthesized.
What causes the rotation of the γ subunit of ATP synthase? How does this rotation promote ATP synthesis?
The movement of H+ through the contact site between the c and a subunits causes the γ subunit to rotate. As it rotates, it sequentially alters the conformation of the β subunits, where ATP is made. This causes (1) ADP and Pi to bind with moderate affinity, (2) ADP and Pi to bind very tightly such that ATP is made, and (3) ATP to be released.
How is glucose breakdown regulated to avoid the overproduction of ATP and NADH? What would be some potentially harmful consequences if glucose metabolism was not regulated properly?
The phases of glucose metabolism are regulated in a variety of ways. For example, key enzymes in glycolysis and the citric acid cycle are regulated by the availability of their substrates and by feedback inhibition. The electron transport chain is regulated by the ATP/ADP ratio. Such regulation ensures that a cell does not waste energy making ATP when it is in sufficient supply. Also, the production of too much NADH is potentially harmful because at high levels it has the potential to haphazardly donate its electrons to other molecules and promote the formation of free radicals, highly reactive chemicals that damage DNA and cellular proteins.
Discuss the advantages and disadvantages of aerobic respiration, anaerobic respiration, and fermentation.
Fill In
Read more about PET scans in other sources. Which types of cancers are most easily detected by this procedure, and which types are not readily detected? Is the ability to detect cancer via a PET scan related to the level of oxygen within a tumor?
Fill In
Which of the following is the best description of the process of cellular respiration?
Multiple choice question.
A means to extract energy from organic molecules
A means to utilize ATP in cells
A means to extract energy from oxygen
A means to extract energy from inorganic molecules
A
The main product of cellular respiration is
Multiple choice question.
oxygen
ATP
carbon dioxide
organic molecules
B
Glucose contains covalent bonds that store a large amount of ______.
Multiple choice question.
water
kinetic energy
ATP
chemical energy
chemical energy
What is the order of glucose breakdown?
Glycolysis, breakdown of pyruvate, citric acid cycle, and oxidative phosphorylation
Which of the following are end products of glycolysis?
Multiple select question.
Pyruvate
Oxygen gas
ATP
NADH
Pyruvate
ATP
NADH
The metabolic reactions that a cell uses to get energy from food molecules and release waste products are collectively called ______.
Multiple choice question.
cellular respiration
chemical respiration
oxidative phosphorylation
glycolysis
cellular respiration
Glycolysis occurs in the ______.
Multiple choice question.
plasma membrane
mitochondrion
cristae membrane
cytosol
cytosol
The primary aim of cellular respiration is to produce molecules of __________ which provide energy to the cell.
ATP, adenosinetriphosphate, or adenosine triphosphate
The pyruvate molecule produced in glycolysis undergoes a reaction which results in the production of one __________ group and one CO2 molecule.
acetyl, acetyl CoA, or acetyl-CoA
The ______ bonds in glucose store large amounts of energy.
Covalent
During glycolysis, one molecule of
______, is broken down into two molecules of pyruvate, driving the synthesis of ATP.
Glucose
Select all that apply
What four pathways are involved in the breakdown of glucose to carbon dioxide and water?
Multiple select question.
Photosynthesis
Citric acid cycle
Oxidative phosphorylation
Breakdown of pyruvate
Glycolysis
Gluconeogenesis
Citric acid cycle
Oxidative phosphorylation
Breakdown of pyruvate
Glycolysis
Tumors provide a favorable environment for glycolysis because their internal regions tend to be deficient in ______.
Multiple choice question.
NAD+
glucose
oxygen
ATP
oxygen
Glycolysis is the breakdown of glucose into ______.
Multiple choice question.
two pyruvate molecules
six carbon dioxide molecules
two citric acid molecules
three acetyl groups
two pyruvate molecules
While glycolysis occurs in the ___________
in eukaryotic cells, the remaining steps of respiration occur in the ___________
of the cell.
Cytosol/mitochondria
True or false: Glycolysis occurs in the mitochondria.
True false question.
True
False
False
When a carbon dioxide is removed from pyruvate, the product is a(n) _______
group, which then attaches to coenzyme A.
Acetyl
What are the products of the breakdown of a single pyruvate molecule?
Multiple select question.
One ATP molecule
Two NADH molecules
One acetyl group
One CO2
Two acetyl groups
One NADH molecule
One acetyl group
One CO2
One NADH molecule
Glycolysis involves the breakdown of one molecule of glucose into ______.
Multiple choice question.
one molecule of pyruvate and one molecule of acetyl-CoA
one molecule of pyruvate and three molecules of CO2
three molecules of acetyl-CoA
two molecules of pyruvate
two molecules of pyruvate
In the first reaction of the citric acid cycle, oxaloacetate, which contains ______ carbons, is combined with acetyl-CoA, which contains ______ carbons in its acetyl group, to produce citric acid, which contains ______ carbons.
Multiple choice question.
3; 3; 6
3; 1; 4
5; 1; 6
4; 2; 6
4; 1; 5
2; 2; 4
4, 2, 6
True or false: Within tumors, glycolysis is favored under hypoxic conditions.
True false question.
True
False
True
What energy intermediates are produced in the citric acid cycle?
Multiple select question.
Pyruvate
Acetyl-CoA
NAD+
NADH
GTP
FADH2
NADH
GTP
FADH2
In order for cellular respiration to continue, the pyruvate produced in glycolysis must be transported into the ______.
Multiple choice question.
mitochondrion
stroma
electron transport chain
cytosol
mitochondrion
During cellular respiration, acetyl-CoA is formed during a reaction that also:
Multiple choice question.
attaches coenzyme A to pyruvate
reduces pyruvate
removes a CO2 from pyruvate
removes coenzyme A from pyruvate
removes a CO2 from pyruvate
In the final stage of glucose metabolism, the high-energy electrons from NADH and FADH2 are removed and used to produce more ATP. This process is called _______ ____________
Oxidative phosphorylation
As a result of the reactions of the citric acid cycle, the carbons from acetyl CoA are released as:
Multiple choice question.
NADH
pyruvate
CO2
ATP
CO2
The structural components of the electron transport chain include which of the following?
Multiple select question.
Small organic molecules
NADH and FADH2
Protein complexes
Carbohydrate complexes
Oxygen gas
Small organic molecules
Protein complexes
Each turn of the citric acid cycle produces ______.
Multiple choice question.
2 NADH
2 NADH and 2 FADH2
3 NAD+ and 1 FAD
3 NADH and 1 FADH2
2 NAD+ and 2 FAD
3 NADH and 1 FADH2
The final electron acceptor in the electron transport chain is ______.
Multiple choice question.
oxygen
carbon dioxide
FADH2
NADH
oxygen
During oxidative phosphorylation, ATP synthesis is coupled to ______.
Multiple choice question.
the breakdown of glucose into CO2
the entry of acetyl-CoA into the citric acid cycle
the synthesis of NADH and FADH2
the removal of high-energy electrons from NADH and FADH2
the removal of high-energy electrons from NADH and FADH2
During oxidative phosphorylation, ATP synthase adds a phosphate group to:
Multiple choice question.
ATP
ADP
NADH
NAD+
FADH2
ADP
Electrons from FADH2 are transferred to succinate reductase and then to a small organic molecule called __________
ubiquinone, coenzymeQ, or oxygen
In eukaryotic cells, the electron transport chain is located in the ______.
Multiple choice question.
cytosol
outer mitochondrial membrane
mitochondrial matrix
inner mitochondrial membrane
plasma membrane
inner mitochondrial membrane
Cyanide is lethal to cells because it ______.
Multiple choice question.
creates holes in the mitochondrial membranes
inhibits the flow of electrons along the ETC
denatures two key enzymes in the citric acid cycle
blocks the conversion of pyruvate to acetyl-CoA
inhibits the flow of electrons along the ETC
The second event in oxidative phosphorylation is the production of ATP by the enzyme ATP __________
.
synthase
During aerobic respiration, the final electron acceptor in the electron transport chain is _________
oxygen
Which of the following best describes the chemical reactions of oxidative phosphorylation?
Multiple choice question.
NADH is reduced and ATP is produced.
NADH is oxidized and ATP is produced.
NADH is oxidized and ATP is consumed.
NADH is reduced and ATP is consumed.
NADH is oxidized and ATP is produced.
True or false: The flow of electrons through the electron transport chain requires an input of energy.
True false question.
True
False
False; it is exergonic
Arrange the molecules of the electron transport chain in the order in which they receive electrons, beginning at the top with the first molecule to receive electrons and ending at the bottom with the final electron acceptor.
Oxygen Cytochrome b-c1 Ubiquinone Cytochrome c Cytochrome oxidase NASDH dehydrogenase
NADH dehydrogenase Ubiquinone Cytochrome b-c1 Cytochrome c Cytochrome oxidase Oxygen
Which of these is a light-driven H+ pump found in archaea?
Multiple choice question.
Chymotrypsin
Calmodulin
Glycophorin
Bacteriorhodopsin
Bacteriorhodopsin
One important component of the electron transport chain is cytochrome oxidase. Which of the following inhibits this complex?
Multiple choice question.
Ricin
Cyanide
Arsenic
Tetanus toxin
Snake venom
Cyanide
ATP synthase functions like a ______.
Multiple choice question.
rotary machine
lever
pulley system
spring
rotary machine
During oxidative phosphorylation, ATP is produced by the enzyme:
Multiple choice question.
ATP synthase
ATP oxidase
ATP protease
citrate synthetase
ATP synthase
Which of the following molecules are used as energy sources by living organisms?
Multiple select question.
Sugars
Amino acids
Fatty acids
Water
Molecular oxygen
Sugars
Amino acids
Fatty acids
When electrons are transferred to oxygen in the final step of the electron transport chain, a molecule of
_____________ is produced.
H2O
An environment where oxygen is absent is termed __________.
anaerobic or anoxic
Hypoxic or dysoxic is low concentration of oxygen – between 1 to 30% saturation
The flow of electrons through the electron transport chain is ______.
Multiple choice question.
exergonic
endergonic
neither exergonic nor endergonic
exergonic
What type of pathway produces ATP by substrate-level phosphorylation without any net oxidation of organic molecules?
Multiple choice question.
Fermentation
Anaerobic respiration
Aerobic respiration
Citric acid cycle
Fermentation
Bacteriorhodopsin is a proton pump found in some species of archaea. The energy that bacteriorhodopsin uses to pump protons comes from ______.
Multiple choice question.
ATP hydrolysis
light
an electron transport chain
ATP synthesis
Light
At the end of the electron transport chain, ______ catalyzes the transfer of electrons to O2.
Multiple choice question.
chaperone
ubiquinone
cytochrome oxidase
cytochrome b-c1
cytochrome oxidase
What type of motion is coupled to the synthesis of ATP by the enzyme ATP synthase?
Multiple choice question.
Vibration
Spinning
Oscillation
Spinning
True or false: Some organisms can only use oxygen as a final electron acceptor.
True false question.
True
False
True
Select the organic molecules obtained from food that are most typically used as energy sources.
Multiple select question.
Fats
Nucleotides
Carbohydrates
Proteins
Fats
Carbohydrates
Proteins
What problem results from the buildup of NADH and decrease of NAD+ under anaerobic conditions?
Multiple choice question.
A decrease in NAD+ levels can kill the cell because NAD+ is needed to release electrons to the ETC.
High concentrations of NADH can lead to the release of free radicals, which can damage DNA and proteins.
No problem results. High concentrations of NADH facilitate glycolysis.
High concentrations of NADH can lead to the release of free radicals, which can damage DNA and proteins.
Which term is used to describe an environment that lacks oxygen?
Multiple choice question.
Aerobic
Anabolic
Catabolic
Anaerobic
Anaerobic
How is ATP produced during fermentation?
Multiple choice question.
Substrate-level phosphorylation
Oxidative phosphorylation using O2 as the final electron acceptor
Oxidative phosphorylation using a molecule other than O2 as the final electron acceptor
Substrate-level phosphorylation
Muscle cells overcome the buildup of NADH and decrease of NAD+ under anaerobic conditions by ______.
Multiple choice question.
reducing pyruvate to citrate
oxidizing pyruvate to citrate
oxidizing pyruvate to lactate
reducing pyruvate to lactate
reducing pyruvate to lactate
What is the outcome of aerobic respiration?
Multiple choice question.
O2 is reduced to H2O
O2 is oxidized to H2O
O2 and H2 are joined to form H2O
H2O is broken down into O2 and H2
O2 is reduced to H2O
Many organisms, including animals and yeasts, can only use _________
as a final electron acceptor in their electron transport chains.
Oxygen
What happens during the fermentation reactions that occur in muscle cells?
Multiple select question.
NADH is converted to lactate.
Pyruvate is reduced to lactate.
NADH is oxidized to NAD+.
Pyruvate is broken down to acetyl-CoA and CO2.
Pyruvate is reduced to lactate.
NADH is oxidized to NAD+.
Under anaerobic conditions, high levels of ______ may cause the production of free radicals.
Multiple choice question.
FADH2
NADH
NAD+
FADH
NADH
Which of these organic molecules can be produced during fermentation reactions?
Multiple select question.
Lactate
Glucose
Glycerol
Acetyl-CoA
Ethanol
Lactate
Ethanol
What molecule is produced during fermentation in muscle cells?
Multiple choice question.
Glucose
Lactose
Citrate
Lactate
Lactate
The complete breakdown of glucose in the presence of oxygen yields 34 to 38 ATP molecules, but the breakdown of glucose to lactate or ethanol yields a net of only ____________ ATP molecules.
2
At the end of the electron transport chain, ______ catalyzes the transfer of electrons to O2.
Multiple choice question.
cytochrome b-c1
ubiquinone
cytochrome oxidase
chaperone
cytochrome oxidase
When a muscle is working strenuously and becomes anaerobic, pyruvate from glycolysis is reduced to lactate to allow the oxidation of ______.
Multiple choice question.
NAD+ to NADH
NADH to NAD+
nitrate to nitrite
H2O to H3O+
NADH to NAD+
The breakdown of glucose to lactate or ethanol as a final end product is an example of _________
Fermentation
Aerobic respiration yields ______ ATP molecules per glucose, while fermentation typically yields ______ ATP molecules per glucose.
38-42 ; 2
34-38 ; 4
2 ; 34-38
4 ; 34-38
34-38 ; 2
34-38 ; 2
[Quiz]
If an organism is missing the transport protein for pyruvate on the mitochondrial membrane, what is the most likely effect?
Question 1 options:
The organism cannot carry out glycolysis
The organism cannot carry out fermentation
The organism cannot carry out the preparation reaction
The organism cannot carry out photosynthesis
The organism cannot carry out fermentation WRONG
[Quiz]
Cytochrome oxidase is the last enzyme in the electron transport chain. Cyanide is a competitive inhibitor of this enzyme. Why is cyanide fatal to humans?
Question 2 options:
Glycolysis is inhibited
The Citric Acid cycle cannot be initiated
The electron transport chain is shut down
Pyruvate is not converted to acetyl-CoA
NAD can no longer be reduced to NADH
The electron transport chain is shut down
[Quiz]
What is the overall goal of cellular respiration?
Question 3 options:
Use the energy in glucose to make ATP
Use solar energy to make ATP
Use solar energy to make glucose
Use the energy in glucose to break down sugars
Use the energy in glucose to make ATP
[Quiz]
A baker was making bread but realized that his yeast were no longer alive. What impact will this have on his bread?
Question 4 options:
It will not rise
It will taste sour due to the increased pH
It will rise too high and spread over the edges of the pan.
It will not rise
[Quiz]
Based on the glycolysis pathway below, what enzyme catalyzes the cleavage reaction?
Hexokinase
Pyruvate kinase
Phosphofructokinase
Fructose bisphosphate aldose
Phosphoglucose isomerase
Fructose bisphosphate aldose
[Quiz]
Bread made with yeast is lighter and fluffier than bread made without yeast. This is because yeast
Question 6 options:
Carries out the citric acid cycle to produce oxygen gas, which adds bubbles to the dough
Carries out fermentation to produce lactic acid, which breaks down gluten
Carries out fermentation to produce carbon dioxide, which adds bubbles to the dough
Carries out the citric acid cycle to produce carbon dioxide, which adds bubbles to the dough
Carries out fermentation to produce carbon dioxide, which adds bubbles to the dough
[Quiz]
If you have been running hard, the body often switches from cellular respiration and starts producing lactic acid. Why?
Question 7 options:
Cellular respiration is not as efficient as fermentation
Cells have depleted their oxygen stores
Lactic acid causes the number of mitochondria in cells to increase
Lactic acid increases the endurance of muscles
Both B and D
Both B and D WRONG
[Quiz]
Which of these is not the result of the citric acid cycle?
Question 8 options:
OAA is reformed
High energy electron carriers are formed
Carbon dioxide is produced
ATP is made through ATP synthase
ATP is made through ATP synthase
[Quiz]
Why is the formation of ATP by ATP synthase referred to as oxidative phosphorylation?
Question 9 options:
A phosphate is transferred from oxygen to ADP to form ATP
Oxygen provides the mechanical energy that is used to create ATP from ADP
Oxygen is the final electron acceptor in the electron transport chain, which creates the proton gradient necessary to power ATP synthase
ADP combines with oxygen to form ATP
Oxygen is the final electron acceptor in the electron transport chain, which creates the proton gradient necessary to power ATP synthase
[Quiz]
When pyruvate is converted to Acetyl-CoA, it loses a proton and its associated electron. This reaction is an example of
Question 10 options:
Oxidation
Reduction
Dehydration
Hydrolysis
Hydrolysis WRONG
[Quiz]
In order to determine if the patient with the blood results shown here could complete glycolysis, what substance would you test for in her blood?
Blood Metabolic Panel
Blood Glucose
+
Glucose-6-phosphate
++
Fructose-6-phosphate
++
Fructose-1,6,bisphosphate
++
Glyceraldehyde-3-phosphate
++
1,3-bisphosphoglycerate
++
Phosphoenolpyruvate
++
Pyruvate
-
ATP
-
Red Blood Cell Concentration
-
Question 11 options:
Glucose-6-phosphate
Fructose-6-phosphate
Glyceradlehyde-3-phosphate
Pyruvate
Pyruvate kinase
Pyruvate kinase WRONG
[Quiz]
A genetic defect in some humans causes a slight decrease in the number of ATP synthase proteins on their mitochondrial membranes. What symptoms would you expect these individuals to exhibit?
Question 12 options:
Hyperactive thyroid
Increased metabolic rate
Increased growth rate
Increased fatigue and lethargy
Increased fatigue and lethargy
[Quiz]
Why does the citric acid cycle spin twice for each glucose in cellular respiration?
Question 13 options:
Because it needs to make more pyruvate
Because there are two acetyl-CoA formed for each glucose
Because the H+ must be pumped into the intermembrane space
Because the oxidative phosphorylation process take twice as long as glycolysis
Because there are two acetyl-CoA formed for each glucose
[Quiz]
If you wanted to test red blood cells for their ability to complete glycolysis, what compound would you try to detect?
Question 14 options:
Fructose-6-phosphate
Aldolase
Pyruvate
Phosphofructokinase
Dihydroxyacetone phosphate
Aldolase WRONG
[Quiz]
The electron transport chain is used to create a proton gradient across the mitochondrial membrane. This proton gradient represents
Question 15 options:
Kinetic energy
Potential energy
Mechanical energy
Heat
Potential energy
