Quiz 7 Biology

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In photosynthetic cells, synthesis of ATP by the chemiosmotic mechanism occurs during
a. both photosynthesis and respiration.
b. respiration only.
c. photosynthesis only.
d. photorespiration only.
both photosynthesis and respiration
Plants photosynthesize only in the light. Plants respire
a. both in light and dark.
b. in the dark only.
c. in the light only.
d. never-they get their ATP from photophosphorylation.
both in light and dark
The oxygen consumed during cellular respiration is involved directly in which process or event?
a. The citric acid cycle
b. Accepting electrons at the end of the electron transport chain
c. The phosphorylation of ADP to form ATP
d. Glycolysis
accepting electrons at the end of the electron transport chain
Which of the following produces the most ATP when glucose (C6H12O6) is completely oxidized to carbon dioxide (CO2) and water?
a. glycolysis
b. citric acid cycle
c. oxidation of pyruvate to acetyl CoA
d. oxidative phosphorylation (chemiosmosis)
oxidative phosphorylation (chemiosmosis)
Which metabolic pathway is common to both fermentation and cellular respiration of a glucose molecule?
a. reduction of pyruvate to lactate
b. glycolysis
c. the citric acid cycle
d. synthesis of acetyl CoA from pyruvate
glycolysis
As electrons are being transported down the electron transport chain from photosystem II to photosystem I
a. all of the energy that is released is used to generate a proton gradient
b. some of the energy that is released is used to form ATP
c. some of the energy that is released is used to generate a proton gradient
d. some of the energy that is released is stored in the form of covalent bonds
some of the energy that is released is used to generate a proton gradient
In addition to ATP, what are the end products of glycolysis?
a. CO2 and pyruvate
b. CO2 and H2O
c. CO2 and NADH
d. NADH and pyruvate
NADH and pyruvate
Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?
a. electrons and H+
b. H2O and O2
c. ATP and NADPH
d. CO2 and glucose
ATP and NADPH
Which process in eukaryotic cells will proceed normally whether oxygen (O2) is present or absent?
a. oxidative phosphorylation
b. glycolysis
c. chemiosmosis
d. electron transport
glycolysis
Synthesis of ATP by the chemiosmotic mechanism occurs during
a. Both photosynthesis and respiration
b. Respiration
c. Neither photosynthesis nor respiration
d. Photosynthesis
both photosynthesis and respiration
Why is less ATP produced by anaerobic respiration than by aerobic respiration?
a. All of these answers are correct.
b. Anaerobic respiration does not make use of an electron transport chain.
c. Anaerobic respiration does not make use of the citric acid cycle.
d. Anaerobic respiration uses a final electron acceptor that is less electronegative than O2, which is used as the final electron acceptor in aerobic respiration.
anaerobic respiration uses a final electron acceptor that is less electronegative than O2, which is used as the final electron acceptor in aerobic respiration
What is the term for metabolic pathways that release stored energy by breaking down complex molecules?
a. catabolic pathways
b. thermodynamic pathways
c. bioenergetic pathways
d. anabolic pathways
catabolic pathways
Photosynthesis may be carried out
a. only by certain eukaryotes but by any prokaryotes
b. only by prokaryotes, which evolved prior to eukaryotes
c. only by eukaryotes, as it requires the presence of chloroplasts, which are membrane-bound organelles
d. only by certain eukaryotes and certain prokaryotes
only by certain eukaryotes and certain prokaryotes
Which of the following statements about the special chlorophyll a
molecules that are part of reaction-center complexes is TRUE?
a. P700+ is part of photosystem II and is such a strong oxidizing agent it can strip an electron from water.
b. P680+ is part of photosystem II and is such a strong oxidizing agent it can strip an electron from water.
c. P680+ is part of photosystem II and is such a strong reducing agent it can strip an electron from water.
d. P700+ is part of photosystem II and is such a strong reducing agent it can strip an electron from water.
P680+ is part of photosystem II and is such a strong oxidizing agent it can strip an electron from water
In prokaryotes, the respiratory electron transport chain is located
a. in the plasma membrane.
b. in the cytoplasm.
c. in the mitochondrial outer membrane.
d. in the mitochondrial inner membrane.
in the plasma membrane
An important difference between oxidative phosphorylation and photophosphorylation is
a. oxidative phosphorylation produces ATP whereas photophosphorylation produces ADP
b. oxidative phosphorylation uses up NADH whereas photophosphorylation generates NADPH
c. oxidative phosphorylation uses energy from food to form a proton gradient whereas photophosphorylation uses energy from light to form a proton gradient
d. both "b" and "c" are correct
both b and c are correct
The pH of the inner thylakoid space and of the stroma have been measured. Which, if any, relationship would you expect to find?
a. The pH within the inner thylakoid space is the same as that of the stroma.
b. The pH within the inner thylakoid space is greater than that of the stroma.
c. The pH within the inner thylakoid space is less than that of the stroma.
d. There is no consistent relationship.
the pH within the inner thylakoid space is less than that of the stroma
In cellular respiration, the energy for most ATP synthesis is supplied by
a. converting oxygen to ATP.
b. a proton gradient across a membrane.
c. high energy phosphate bonds in organic molecules.
d. transferring electrons from organic molecules to pyruvate.
a proton gradient across a membrane
Which statement describes the functioning of photosystem II?
a. Light energy excites electrons in the thylakoid membrane electron transport chain.
b. The electron vacancies in P680+ are filled by electrons derived from water.
c. The P680 chlorophyll donates a pair of protons to NADP+, which is thus converted to NADPH.
d. Photons are passed along to a reaction-center chlorophyll.
the electron vacancies in P680+ are filled by electrons derived from water
An electron loses potential energy when it
a. shifts to a more electronegative atom.
b. shifts to a less electronegative atom.
c. moves further away from the nucleus of the atom.
d. increases its kinetic energy.
shifts to a more electronegative atom
During aerobic respiration, H2O is formed. Where does the oxygen atom for the formation of the water come from?
a. molecular oxygen (O2)
b. glucose (C6H12O6)
c. carbon dioxide (CO2)
d. pyruvate (C3H3O3-)
molecular oxygen (O2)
You have a friend who lost 7 kg (about 15 pounds) of fat on a regimen of strict diet and exercise. How did the fat leave her body?
a. It was converted to ATP, which weighs much less than fat.
b. It was converted to heat and then released.
c. It was released as CO2 and H2O.
d. It was converted to urine and eliminated from the body.
it was released as CO2 and H2O
A molecule that is phosphorylated
a. has an increased chemical potential energy; it is primed to do cellular work.
b. has less energy than before its phosphorylation and therefore less energy for cellular work.
c. has a decreased chemical reactivity; it is less likely to provide energy for cellular work.
d. has been reduced as a result of a redox reaction involving the loss of an inorganic phosphate.
has an increased chemical potential energy; it is primed to do cellular work
When an electron moves from
a. the second to the third subunit of the electron transport chain, energy is released that can be used to do work
b. the first to the second subunit of the electron transport chain, energy is released that can be used to do work
c. all of these statements are true
d. NADH to the first subunit of the electron transport chain, energy is released that can be used to do work
all of these statements are true
The transfer of an electron from a P680 chlorophyll a molecule to the primary electron acceptor of photosystem II
a. will only occur if the P680 molecule first receives an electron from a pigment molecule in the light-harvesting complex
b. will only occur if one P680 molecule first receives an electron from the other P680 molecule
c. will only occur if the P680 molecule is able to directly absorb the energy from a photon of light
d. will only occur if the P680 molecule has an electron that is sufficiently excited (i.e. of sufficiently high energy)
will only occur if the P680 molecule has an electron that is sufficiently excited
The enzyme that attaches CO2 to a 5-carbon long sugar to form a 6-carbon long molecule is
a. photosynthase
b. carbon dioxide synthase
c. ribulose bisphosphate carboxylase oxygenase, or "Rubisco"
d. polymerase
rubisco
Besides CO2 and H2O, to produce sugars through the reactions of the Calvin cycle cells also require
Select one:
a. ATP as an energy source to "drive" the otherwise exergonic reaction and NADPH as an oxidizing agent.
b. ATP as an energy source to "drive" the otherwise endergonic reaction and NADPH as a reducing agent.
c. ATP as an energy source to "drive" the otherwise endergonic reaction and NADPH as an oxidizing agent.
d. ATP as an energy source to "drive" the otherwise exergonic reaction and NADPH as a reducing agent.
ATP as an energy source to drive the otherwise endergonic reaction and NADPH as a reducing agent
Brown fat cells produce a protein called thermogenin in their mitochondrial inner membrane. Thermogenin is a channel for facilitated transport of protons across the membrane. What will occur in the brown fat cells when they produce thermogenin?
a. ATP synthesis and heat generation will both increase.
b. ATP synthesis will decrease, and heat generation will increase.
c. ATP synthesis will increase, and heat generation will decrease.
d. ATP synthesis and heat generation will both decrease.
ATP synthesis will decrease and heat generation will increase
During the light reactions of photosynthesis, energy from light is used to
a. produce NADPH
b. produce ATP
c. produce ATP and NADPH
d. produce ATP and NADP+
produce ATP and NADPH
Which of the following does not occur during the Calvin cycle?
a. consumption of ATP
b. oxidation of NADPH
c. carbon fixation
d. release of oxygen
release of oxygen
The movement of protons that occurs during transfer of electrons through the electron transport chain is an example of
a. transport via channel proteins
b. active transport
c. transport via carrier proteins
d. facilitated diffusion
active transport
Which of the following occurs in the cytosol of a eukaryotic cell?
a. citric acid cycle
b. oxidation of pyruvate to acetyl CoA
c. fermentation and chemiosmosis
d. glycolysis and fermentation
glycolysis and fermentation
If photosynthesizing green algae are provided with CO2 synthesized with heavy oxygen (18O), later analysis will show that all but one of the following compounds produced by the algae contain the 18O label. That one is
a. ribulose bisphosphate (RuBP).
b. glyceraldehyde 3-phosphate (G3P).
c. 3-phosphoglycerate.
d. O2
O2
Carbon dioxide (CO2) is released during which of the following stages of cellular respiration?
a. fermentation and glycolysis
b. glycolysis and the oxidation of pyruvate to acetyl CoA
c. the citric acid cycle and oxidative phosphorylation
d. oxidation of pyruvate to acetyl CoA and the citric acid cycle
oxidation of pyruvate to acetyl CoA and the citric acid cycle
High levels of citric acid inhibit the enzyme phosphofructokinase, a key enzyme in glycolysis. Citric acid binds to the enzyme at a different location from the active site. This is an example of
a. competitive inhibition.
b. the specificity of enzymes for their substrates.
c. allosteric regulation.
d. an enzyme requiring a cofactor.
allosteric regulation
Drugs known as uncouplers facilitate diffusion of protons across the membrane. When such a drug is added, what will happen to ATP synthesis and oxygen consumption, if the rates of glycolysis and the citric acid cycle stay the same?
a. ATP synthesis will decrease; oxygen consumption will stay the same
b. Both ATP synthesis and oxygen consumption will decrease
c. Both ATP synthesis and oxygen consumption will increase
d. ATP synthesis will increase; oxygen consumption will decrease
ATP synthesis will decrease; oxygen consumption will stay the same
Which of the events listed below occurs in the light reactions of photosynthesis?
a. Carbon dioxide is incorporated into PGA.
b. NADP+ is produced.
c. ATP is phosphorylated to yield ADP.
d. Energy from light is absorbed and funneled to a reaction-center chlorophyll a molecule.
energy from light is absorbed and funneled to a reaction-center chlorophyll a molecule
The enzyme (ribulose bisphosphate carboxylase oxygenase, or "Rubisco") that attaches CO2 to a 5-carbon long sugar to form a 6-carbon long molecule,
a. causes the reaction it catalyzes to be a spontaneous process
b. converts the reaction it catalyzes from an endergonic to an exergonic reaction
c. is very abundant on earth because it is very slow at its job
d. requires energy directly from ATP to catalyze its reaction
is very abundant on earth because it is very slow at its job
The absorption spectrum for chlorophyll a and the action spectrum for photosynthesis are not identical to each other. Why are they not identical?
a. Green and yellow wavelengths inhibit the absorption of red and blue wavelengths.
b. Oxygen given off during photosynthesis interferes with the absorption of light.
c. Other pigments absorb light in addition to chlorophyll a.
d. Bright sunlight destroys photosynthetic pigments.
other pigments absorb light in addition to chlorophyll a
Where would you expect the genes that encode the components of the photosynthetic machinery to be located?
a. all in the nuclear DNA
b. all in the chloroplast DNA
c. some in the chloroplast DNA and some in the thylakoid DNA
d. some in the nuclear DNA, some in the chloroplast DNA
some in the nuclear DNA, some in the chloroplast DNA
The light reactions of photosynthesis supply the Calvin cycle with
a. light energy.
b. ATP and NADPH.
c. H2O and NADPH.
d. CO2 and ATP.
ATP and NADPH
The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction
a. loses electrons and gains energy
b. loses electrons and loses energy
c. gains electrons and loses energy
d. gains electrons and gains energy
loses electrons and loses energy
When electrons move closer to a more electronegative atom, what happens?
a. Energy is consumed and he more electronegative atom is oxidized
b. Energy is released and he more electronegative atom is oxidized
c. Energy is consumed and the more electronegative atom is reduced
d. Energy is released and the more electronegative atom is reduced
energy is released and the more electronegative atom is reduced
Which of the following is an important difference between aerobic and anaerobic respiration
a. All of these answers are correct.
b. Anaerobic respiration results in the production of lactic acid (lactate) or ethanol.
c. Aerobic, but not anaerobic, respiration makes use of the citric acid cycle.
d. The electron transport chain used in aerobic respiration uses O2 as the final electron acceptor whereas the electron transport chain used in anaerobic respiration uses something other than O2 as the final electron acceptor.
the electron transport chain used in aerobic respiration uses O2 as the final electron acceptor whereas the electron transport chain used in anaerobic respiration uses something other than O2 as the final electron acceptor
Where does glycolysis take place in eukaryotic cells?
a. mitochondrial inner membrane
b. mitochondrial matrix
c. mitochondrial intermembrane space
d. cytosol
cytosol
Which of the following shows the molecules in the order of least to most electronegative?
a. O2, NADH, e- transport chain
b. NADH, e- transport chain, O2
c. NADH, O2, e- transport chain
d. O2, e- transport chain, NADH
NADH, e- transport chain, O2
During photosynthesis, the carbon in CO2 is reduced, helping to form sugar molecules. Which of the following statements about this process is TRUE?
a. NADPH removes electrons from CO2
b. NADP+ removes electrons from CO2
c. NADPH donates electrons to CO2
d. NADP+ donates electrons to CO2
NADPH donates electrons to CO2
Which of the following statements best describes the relationship between photosynthesis and respiration?
a. ATP molecules are produced in photosynthesis and used up in respiration.
b. Photosynthesis stores energy in complex organic molecules, whereas respiration releases it.
c. Respiration is anabolic and photosynthesis is catabolic.
d. Photosynthesis occurs only in plants and respiration occurs only in animals.
photosynthesis stores energy in complex organic molecules, whereas respiration releases it
In photosynthesis, "resonance energy transfer" refers to
a. the transfer of electrons between pigment molecules
b. the transfer of energy from an excited electron in one pigment molecule to an electron in a different pigment molecule
c. all of these answers are correct
d. the transfer of energy from an excited proton in one pigment molecule to a proton in a different pigment molecule
the transfer of energy from an excited electron in one pigment molecule to an electron in a different pigment molecule
Which pathways generate reduced electron carriers?
a. the citric acid cycle and glycolysis
b. glycolysis only
c. the citric acid cycle only
d. none of these answers are correct
the citric acid cycle and glycolysis
In mitochondria, during chemiosmosis protons move from the intermembrane space to the matrix, whereas in chloroplasts, during chemiosmosis protons move from
a. the inter-thylakoid space to the stroma.
b. the stroma to the inter-thylakoid space.
c. the matrix to the stroma.
d. the intermembrane space to the matrix.
the inter-thylakoid space to the stroma
Why are carbohydrates and fats considered high-energy foods?
a. They can have very long carbon skeletons.
b. They are easily reduced.
c. They have a lot of electrons associated with hydrogen.
d. They have a lot of oxygen atoms.
they have a lot of electrons associated with hydrogen
Where do the enzymatic reactions of the Calvin cycle take place?
a. thylakoid space
b. stroma of the chloroplast
c. matrix of the mitochondria
d. thylakoid membranes
stroma of the chloroplast
In vertebrate animals, brown fat tissue's color is due to abundant blood vessels and capillaries. White fat tissue, on the other hand, is specialized for fat storage and contains relatively few blood vessels or capillaries. Brown fat cells have a specialized protein that dissipates the proton-motive force across the mitochondrial membranes. Which of the following might be the function of the brown fat tissue?
a. to allow the animals to regulate their metabolic rate when it is especially hot
b. to increase the production of ATP
c. to allow other membranes of the cell to perform mitochondrial functions
d. to regulate temperature by converting most of the energy from NADH oxidation to heat
to regulate temperature by converting most of the energy from NADH oxidation to heat
During the chemiosmosis phase of oxidative phosphorylation, potential energy stored during the electron transport phase is converted to energy stored in the form of:
a. NADH
b. lipid
c. ATP
d. a proton gradient
ATP
What are the products of linear photophosphorylation?
a. ADP and NADP+
b. ATP and NADPH
c. ATP and P700
d. P700 and P680
ATP and NADPH
In the reaction shown below

Na and Cl → Na+ and Cl-

a. Na and Cl are the oxidizing agents
b. Na is the reducing agent and Cl is the oxidizing agent
c. Na is the oxidizing agent and Cl is the reducing agent
d. Na and Cl are the reducing agents
Na is the reducing agent and Cl is the oxidizing agent
The purpose of fermentation reactions is
a. to regenerate NAD+ so glycolysis can continue
b. to slow down cellular oxygen consumption when oxygen is scarce
c. to make alcohol or lactic acid that cells can metabolize for energy under anaerobic conditions
d. to make additional ATP when respiration can't make ATP fast enough
regenerate NAD+ so glycolysis can continue
In the thylakoid membranes, what is the main role of the antenna pigment molecules?
a. harvest photons and transfer light energy to the reaction-center chlorophyll
b. concentrate photons within the stroma
c. split water and release oxygen to the reaction-center chlorophyll
d. synthesize ATP from ADP and inorganic phosphate
harvest photons and transfer light energy to the reaction-center chlorophyll
The typical beginning of the pathway of energy transfer that occurs during photosynthesis is
a. energy from a photon of light → a pigment molecule → chlorophyll a→ primary electron acceptor
b. energy from a photon of light → chlorophyll a → a pigment molecule → primary electron acceptor
c. energy from a photon of light → a pigment molecule → primary electron acceptor → chlorophyll a
d. energy from a photon of light → primary electron acceptor → a pigment molecule → chlorophyll a
energy from a photon of light -> a pigment molecule -> chlorophyll a -> primary electron acceptor
In the reaction shown below

CH4 + 2 O2 → CO2 + energy + 2 H2O

a. CH4 is oxidized and O2 is reduced
b. CH4 is reduced and O2 is oxidized
c. CH4 and O2 are oxidized
d. CH4 and O2 are reduced
CH4 is oxidized and O2 is reduced
The direct product of the reaction catalyzed by ribulose bisphosphate carboxylase oxygenase, or "Rubisco"
a. is not a sugar molecule and must be oxidized using electrons from NADPH to form sugar molecules
b. is not a sugar molecule and must be reduced using electrons from NADPH to form sugar molecules
c. is a sugar molecule
d. is not a sugar molecule and must be reduced using electrons from NADP+ to form sugar molecules
is not a sugar molecule and must be reduced using electrons from NADPH to form sugar molecules
Which of the following metabolic processes include glycolysis?
a. aerobic respiration
b. all of these answers are correct
c. fermentation
d. anaerobic respiration
all of these are correct
In the reaction shown below

C6H12O6 + 6 O2 → 6 CO2 + energy + 6 H2O

a. C6H12O6 is oxidized and O2 is reduced
b. C6H12O6 and O2 are oxidized
c. C6H12O6 and O2 are reduced
d. C6H12O6 is reduced and O2 is oxidized
C6H12O6 is oxidized and O2 is reduced
The synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electrochemical gradient, is an example of
a. an endergonic reaction coupled to an exergonic reaction.
b. allosteric regulation.
c. active transport.
d. a reaction with a positive ΔG .
an endergonic reaction coupled to an exergonic reaction
Chemiosmosis
a. serves to generate ATP in both photosynthesis and respiration, but NADPH is produced by chemiosmosis during photosynthesis whereas NADH is used up by chemiosmosis during respiration
b. is found only in respiration.
c. is found only in photosynthesis in plants from hot, arid regions.
d. is identical in both respiration and photosynthesis, and is used to generate oxygen.
serves to generate ATP in both photosynthesis and respiration, but NADPH is produced by chemiosmosis during photosynthesis whereas NADH is used up by chemiosmosis during respiraton
The transport of pyruvate into mitochondria depends on the proton-motive force across the inner mitochondrial membrane. How does pyruvate enter the mitochondrion?
a. active transport
b. diffusion
c. through a channel
d. facilitated diffusion
active transport
The "building blocks" for the production of sugar molecules that occurs during photosynthesis are
a. CO2, ATP and NADPH
b. CO2 and H2O
c. CO2 and ATP
d. CO2, O2 and ATP
CO2 and H2O
The process known as "substrate-level phosphorylation"
a. occurs only during oxidative phosphorylation
b. occurs only during the citric acid cycle
c. occurs only during glycolysis
d. occurs during both glycolysis and the citric acid cycle.
occurs during both glycolysis and the citric acid cycle
In mechanism, photophosphorylation is most similar to
a. oxidative phosphorylation in cellular respiration.
b. carbon fixation.
c. the Calvin cycle.
d. substrate-level phosphorylation in glycolysis.
oxidative phosphorylation in cellular respiration
One function of both alcohol fermentation and lactic acid fermentation is to
a. reduce NAD+ to NADH.
b. oxidize NADH to NAD+.
c. reduce FADH2 to FAD+.
d. reduce FAD+ to FADH2.
oxidize NADH to NAD+
What is proton-motive force?
a. the force required to remove an electron from hydrogen
b. the force that moves hydrogen into the intermembrane space
c. the force exerted on a proton by a transmembrane proton concentration gradient
d. the force that moves hydrogen to NAD+
the force exerted on a proton by a transmembrane proton concentration gradient
Reactions that require CO2 take place in
a. both the light reactions and the Calvin cycle.
b. the light reactions alone.
c. the Calvin cycle alone.
d. neither the light reactions nor the Calvin cycle.
the calvin cycle alone
When a molecule of NAD+ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a proton), the molecule becomes
a. hydrolyzed.
b. dehydrogenated.
c. oxidized.
d. reduced.
reduced
Which of the following sequences correctly represents the flow of electrons during photosynthesis?
a. NADPH → chlorophyll → Calvin cycle
b. H2O → NADPH → Calvin cycle
c. NADPH → electron transport chain → O2
d. H2O → photosystem I → photosystem II
H2O -> NADPH -> Calvin cycle
Reduction of oxygen to form water occurs during
a. respiration only.
b. both photosynthesis and respiration.
c. photosynthesis only.
d. photorespiration only.
respiration only
The reactions that produce molecular oxygen (O2) take place in
a. the Calvin cycle alone.
b. the light reactions alone.
c. both the light reactions and the Calvin cycle.
d. neither the light reactions nor the Calvin cycle.
the light reactions alone
What does the chemiosmotic process in chloroplasts involve?
a. movement of water by osmosis into the thylakoid space from the stroma
b. reduction of water to produce ATP energy
c. formation of glucose, using carbon dioxide, NADPH, and ATP
d. establishment of a proton gradient across the thylakoid membrane
establishment of a proton gradient across the thylakoid membrane
Even though plants carry on photosynthesis, plant cells still use their mitochondria for oxidation of pyruvate. When and where will this occur?
a. in nonphotosynthesizing cells only
b. only in photosynthetic cells in the light, while photosynthesis occurs concurrently
c. in cells that are storing glucose only
d. in all cells all the time
in all cells all the time
When comparing oxidative phosphorylation with photophosphorylation, you should notice that
a. both oxidative phosphorylation and photophosphorylation use up NADH
b. oxidative phosphorylation generates NADH whereas photophosphorylation uses up NADPH
c. both oxidative phosphorylation and photophosphorylation generate NADPH
d. oxidative phosphorylation uses up NADH whereas photophosphorylation generates NADPH
oxidative phosphorylation uses up NADH whereas photophosphorylation generates NADPH
The reactions of the Calvin cycle can take place
a. only at dusk and at dawn
b. only in the light
c. only in the dark
d. in either the dark or the light
in either the dark or the light
When a glucose molecule loses a hydrogen atom as the result of an oxidation-reduction reaction, the molecule becomes
a. hydrogenated.
b. oxidized.
c. reduced.
d. hydrolyzed.
oxidized
The direct energy source that drives ATP synthesis during respiratory oxidative phosphorylation in eukaryotic cells is
a. the thermodynamically favorable transfer of phosphate from glycolysis and the citric acid cycle intermediates to molecules of ADP.
b. the final transfer of electrons to oxygen.
c. the thermodynamically favorable flow of electrons from NADH to the mitochondrial electron transport carriers.
d. the proton-motive force across the inner mitochondrial membrane.
the proton-motive force across the inner mitochondrial membrane
In the thylakoid membranes, what is the main role of the pigment molecules in the light-harvesting complexes?
a. Split water and release oxygen
b. Transfer electrons to ferredoxin and then NADPH
c. Harvest photons and transfer light energy to the reaction-center chlorophyll
d. Synthesize ATP from ADP and Pi
harvest photons and transfer light energy to the reaction-center chlorophyll
During cellular respiration, acetyl CoA accumulates in which location?
a. cytosol
b. mitochondrial inner membrane
c. mitochondrial matrix
d. mitochondrial intermembrane space
mitochondrial matrix
During cellular respiration, what is the direction of energy flow?
a. Chemical bonds in food - to NADH - to a proton gradient - to chemical bonds in ATP
b. Chemical bonds in food - to a proton gradient - to chemical bonds in ATP - to NADH
c. Chemical bonds in food - to NADH - to chemical bonds in ATP - to a proton gradient
d. Chemical bonds in food - to a proton gradient - to NADH - to chemical bonds in ATP
chemical bonds in food - to NADH - to a proton gradient - to chemical bonds in ATP
When electrons flow along the electron transport chain in mitochondria, which of the following changes occurs?
a. NAD+ is oxidized.
b. The electrons gain free energy.
c. The pH of the matrix increases.
d. ATP synthase pumps protons by active transport.
the pH of the matrix increases
During photosynthesis, the carbon in CO2 is reduced, helping to form sugar molecules. Which of the following statements about this process is TRUE?
a. NADP+ is the reducing agent for CO2
b. NADPH is the reducing agent for CO2
c. NADPH is the oxidizing agent for CO2
d. NADP+ is the oxidizing agent for CO2
NADPH is the reducing agent for CO2
If your muscles used alcohol fermentation instead of lactic acid fermentation, which of the following might occur?
a. Your cells would not make ATP under anaerobic conditions.
b. You might become drunk during an intense workout.
c. Your cells would make more ATP under anaerobic conditions.
d. Your cells would recycle less NADH to NAD+ in anaerobic conditions.
you might become drunk during an intense workout
In the reaction shown below

Na and Cl → Na+ and Cl-

a. Na is reduced and Cl is oxidized
b. Na and Cl are reduced
c. Na is oxidized and Cl is reduced
d. Na and Cl are oxidized
Na is oxidized and Cl is reduced
A flask containing photosynthetic green algae and a control flask containing water with no algae are both placed under a bank of lights, which are set to cycle between 12 hours of light and 12 hours of dark. The dissolved oxygen concentrations in both flasks are monitored. Predict what the relative dissolved oxygen concentrations will be in the flask with algae compared to the control flask.

a. The dissolved oxygen in the flask with algae will be higher in the light, but the same in the dark.
b. The dissolved oxygen in the flask with algae will always be higher.
c. The dissolved oxygen in the flask with algae will be higher in the light, but lower in the dark.
d. The dissolved oxygen in the flask with algae will always be lower.
the dissolved oxygen in the flask with algae will be higher in the light, but lower in the dark
An enzyme, ribulose bisphosphate carboxylase oxygenase, or "Rubisco", attaches CO2 to a 5-carbon long sugar to form a 6-carbon long molecule, which
a. has an excited electron
b. is unstable and splits to form two 3-carbon long molecules
c. is a glucose molecule
d. all of these answers are correct
is unstable and splits to form two 3-carbon long molecules
Suppose the interior of the thylakoids of isolated chloroplasts were made acidic and then transferred in the dark to a pH 8 solution. What would be likely to happen?

a. Cyclic photophosphorylation will occur.
b. The Calvin cycle will be activated.
c. The isolated chloroplasts will generate oxygen gas.
d. The isolated chloroplasts will make ATP.
the isolated chloroplasts will make ATP
Which of the following statements best represents the relationships between the light reactions and the Calvin cycle?

a. The light reactions provide ATP and NADPH to the carbon fixation step of the Calvin cycle, and the cycle provides water and electrons to the light reactions.
b. The light reactions provide the Calvin cycle with oxygen for electron flow, and the Calvin cycle provides the light reactions with water to split.
c. The light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, inorganic phosphate, and NADP+ to the light reactions.
d. The light reactions supply the Calvin cycle with CO2 to produce sugars, and the Calvin cycle supplies the light reactions with sugars to produce ATP.
the light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, inorganic phosphate, and NADP+ to the light reactions
The final electron acceptor of the electron transport chain that functions in aerobic oxidative phosphorylation is
a. ADP.
b. water.
c. NAD+.
d. oxygen.
oxygen
During aerobic respiration, electrons travel downhill in which sequence?
a. glucose to ATP to electron transport chain to NADH
b. food to NADH to electron transport chain to oxygen
c. food to glycolysis to citric acid cycle to NADH to ATP
d. food to citric acid cycle to ATP to NAD+
food to NADH to electron transport chain to oxygen
What percentage of living organisms are dependent, directly or indirectly, on food molecules produced via photosynthesis?
a. ~50%
b. 100%
c. the vast majority
d. ~70%
the vast majority
Which of the following most accurately describes what happens along the electron transport chain?
a. Energy of the electrons increases at each step.
b. Each electron carrier alternates between being reduced and being oxidized.
c. ATP is generated at each step.
d. Molecules in the chain give up some of their potential energy.
each electron carrier alternates between being reduced and being oxidized
What is the primary function of the Calvin cycle?
a. split water and release oxygen
b. transport RuBP out of the chloroplast
c. use NADPH to release carbon dioxide
d. synthesize simple sugars from carbon dioxide
synthesize simple sugars from carbon dioxide
During the light reactions of photosynthesis, electrons are transferred
a. from pigment molecules to special chlorophyll a molecules
b. from special chlorophyll a molecules to primary electron acceptors
c. between different pigment molecules in the light-harvesting complex
d. all of these answers are correct
from special chlorophyll a molecules to primary electron acceptors
During the light reactions of photosynthesis
a. the initial source of electrons is H2O and the final electron acceptor is CO2
b. the initial source of electrons is H2O and the final electron acceptor is NADP+
c. the initial source of electrons is O2 and the final electron acceptor is H2O
d. the initial source of electrons is CO2 and the final electron acceptor is H2O
the initial source of electrons is H2O and the final electron acceptor is NADP+
The reactions of the Calvin cycle are
a. exergonic, and thus require a source of free energy to occur
b. endergonic, and thus require a source of free energy to occur
c. endergonic, and thus may proceed spontaneously without a source of free energy
d. exergonic, and thus may proceed spontaneously without a source of free energy
endergonic, and thus require a source of free energy to occur
In the absence of oxygen, yeast cells can obtain energy by fermentation, resulting in the production of
a. ATP, pyruvate, and oxygen.
b. ATP, NADH, and pyruvate.
c. ATP, CO2, and ethanol (ethyl alcohol).
d. ATP, CO2, and lactate.
ATP, CO2, and ethanol
In aerobic metabolism, most of the ATP produced by the oxidation of glucose to carbon dioxide is produced by
a. the Krebs cycle.
b. oxidative phosphorylation.
c. the Calvin cycle.
d. glycolysis.
oxidative phosphorylation
Redox reactions
a. can result in a transfer of electrons
b. can result in a change in electron sharing in covalent bonds
c. both "a" and "b" are correct
d. none of these answers is correct
both a and b are correct
When a pigment molecule in a light-harvesting complex absorbs the energy from a photon of light, an electron in the pigment molecule becomes "excited". What does this mean?
a. The electron has achieved a higher-energy state, meaning that it is located further from the nucleus.
b. The electron has achieved a higher-energy state, meaning that it is located closer to the nucleus.
c. The electron has acquired a greater charge.
d. The electron has acquired greater speed, meaning greater kinetic energy.
the electron has achieved a higher-energy state, meaning that it is located further from the nucleus
When an electron moves from one molecule to another molecule that is more electronegative
a. the electron loses kinetic energy
b. the electron loses potential energy
c. the electron gains potential energy
d. the electron gains kinetic energy
the electron loses potential energy
Which metabolic pathway is common to both cellular respiration and fermentation?
a. the oxidation of pyruvate to acetyl CoA
b. glycolysis
c. the citric acid cycle
d. chemiosmosis
glycolysis
When skeletal muscle cells continue to do work under conditions of insufficient oxygen (e.g. anaerobic exercise), they become fatigued and painful. This is now known to be caused by
a. increase in ethanol.
b. buildup of pyruvate.
c. increase in sodium ions.
d. buildup of lactate.
buildup of lactate
In a plant leaf, the reactions that produce NADH (NADH, not NADPH) occur in
a. the Calvin cycle alone.
b. both the light reactions and the Calvin cycle.
c. the light reactions alone.
d. neither the light reactions nor the Calvin cycle.
neither the light reactions nor the Calvin cycle
A plant has a unique photosynthetic pigment. The leaves of this plant appear to be reddish yellow. What wavelengths of visible light are being absorbed by this pigment?
a. blue, green, and red
b. blue and violet
c. red and yellow
d. green and yellow
blue and violet
In liver cells, the inner mitochondrial membranes are about five times the area of the outer mitochondrial membranes. What purpose must this serve?
a. It increases the surface for oxidative phosphorylation.
b. It allows for an increased rate of the citric acid cycle.
c. It increases the surface for substrate-level phosphorylation.
d. It allows for an increased rate of glycolysis.
it increases the surface for oxidative phosphorylation
Which of the following are directly associated with photosystem I?
a. harvesting of light energy by ATP
b. generation of molecular oxygen
c. receiving electrons from the thylakoid membrane electron transport chain
d. extraction of hydrogen electrons from the splitting of water
receiving electrons from the thylakoid membrane electron transport chain
In a plant cell, where are the ATP synthase complexes located?
a. thylakoid membrane only
b. inner mitochondrial membrane only
c. thylakoid membrane and inner mitochondrial membrane
d. thylakoid membrane and plasma membrane
thylakoid membrane and inner mitochondrial membrane
During photosynthesis, when a pigment molecule in a light harvesting complex absorbs a photon of light
a. energy from the photon causes the pigment molecule to transfer a hydrogen ion, helping to form a hydrogen ion gradient
b. energy from the photon causes an electron to move to a higher energy state
c. energy from the photon causes the pigment molecule to lose an electron
d. energy from the photon causes the pigment molecule to accept an electron from NADPH
energy from the photon causes an electron to move to a higher energy state
Exposing inner mitochondrial membranes to ultrasonic vibrations will disrupt the membranes. However, the fragments will reseal "inside out." These little vesicles that result can still transfer electrons from NADH to oxygen and synthesize ATP. These inside-out membrane vesicles
a. will make ATP from ADP and Pi if transferred to a pH 4 buffered solution after incubation in a pH 7 buffered solution.
b. will hydrolyze ATP to pump protons out of the interior of the vesicle to the exterior.
c. will become alkaline inside the vesicles when NADH is added.
d. will become acidic inside the vesicles when NADH is added.
will become acidic inside the vesicles when NADH is added
Assume a thylakoid is somehow punctured so that the interior of the thylakoid is no longer separated from the stroma. This damage will have the most direct effect on which of the following processes?
a. the splitting of water
b. the flow of electrons from photosystem II to photosystem I
c. the absorption of light energy by chlorophyll
d. the synthesis of ATP
the synthesis of ATP
When an electron moves from one molecule to another molecule that is more electronegative than the first molecule,
a. some of the potential energy that is given up by the electron is lost as heat
b. all of the potential energy that is given up by the electron may be used to do work
c. an endergonic reaction has occurred
d. work must be done on the system to allow the electron to move
some of the potential energy that is given up by the electron is lost as heat
Why is glycolysis described as having an investment phase and a payoff phase?
a. It uses glucose and generates pyruvate.
b. It first uses two stored ATP and then forms four ATP, for a net increase of two ATP.
c. It attaches and detaches phosphate groups.
d. It both splits molecules and assembles molecules.
it first uses two stored ATP and then forms four ATP, for a net increase of two ATP
When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the intermembrane space, the direct result is the
a. creation of a proton-motive force.
b. formation of ATP.
c. lowering of pH in the mitochondrial matrix.
d. reduction of NAD+.
creation of a proton-motive force
Which of the following occur in both aerobic and anaerobic respiration?
a. an electron transport chain
b. citric acid cycle
c. all of these answers are correct
d. glycolysis
all of these answers are correct
Which of the following statements about the light reactions of photosynthesis is FALSE?
a. Upon absorbing the energy from a photon of light, a pigment molecule in the light-harvesting complex may transfer energy from an excited electron to a special chlorophyll a molecule in the reaction-center complex via resonance energy transfer
b. Upon absorbing the energy from a photon of light, pigment molecules in the light-harvesting complex may transfer an excited electron to a special chlorophyll a molecule in the reaction-center complex
c. Upon absorbing energy from an excited electron in a pigment molecule, special chlorophyll a molecules may transfer an electron to a primary electron acceptor.
d. Upon absorbing the energy from a photon of light, a pigment molecule in the light-harvesting complex may transfer energy from an excited electron to another pigment molecule in the light-harvesting complex via resonance energy transfer
upon absorbing the energy from a photon of light, pigment molecules in the light-harvesting complex may transfer an excited electron to a special chlorophyll a molecule in the reaction-center complex
The splitting of carbon dioxide to form oxygen gas and carbon compounds occurs during
a. photorespiration.
b. neither photosynthesis nor respiration.
c. photosynthesis.
d. respiration.
neither photosynthesis nor respiration
Where is ATP synthase located in the mitochondrion?
a. outer membrane
b. mitochondrial matrix
c. cytosol
d. inner membrane
inner membrane
During the process of photosynthesis,
a. 100% of the energy captured from sunlight is transformed into potential energy in the form of a hydrogen ion gradient and then into potential energy in the form of covalent bonds
b. less than 100% of the energy captured from sunlight is transformed into potential energy in the form of covalent bonds and then into potential energy in the form of a hydrogen ion gradient
c. less than 100% of the energy captured from sunlight is transformed into potential energy in the form of a hydrogen ion gradient and then into potential energy in the form of covalent bonds
d. 100% of the energy captured from sunlight is transformed into potential energy in the form of covalent bonds and then into potential energy in the form of a hydrogen ion gradient
less than 100% of the energy captured from sunlight is transformed into potential energy in the form of a hydrogen ion gradient and then into potential energy in the form of covalent bonds
Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the removal of a carbon (CO2) from one molecule of pyruvate?
a. acetyl CoA
b. lactate
c. citrate
d. glyceraldehydes-3-phosphate
acetyl CoA
A spaceship is designed to support animal life for a multiyear voyage to the outer planets of the solar system. Plants will be grown to provide oxygen and to recycle carbon dioxide.
If the power fails and the lights go dark, what will happen to CO2 levels?

a. CO2 will fall because plants will cease to respire in the dark.
b. CO2 will remain balanced because plants will continue to fix CO2 in the dark.
c. CO2 will rise as a result of animal respiration only.
d. CO2 will rise as a result of both animal and plant respiration.
CO2 will rise as a result of both animal and plant respiration
During the electron transport phase of oxidative phosphorylation, most of the energy that is captured for later use is in the form of:

a. CO2
b. a proton gradient
c. ATP
d. NADH
a proton gradient
The transfer of electrons from the primary electron acceptor of photosystem II to the P700+ chlorophyll a molecules of photosystem I is

a. exergonic as the P700+ chlorophyll a molecule is less electronegative than the primary electron acceptor
b. exergonic as the P700+ chlorophyll a molecule is more electronegative than the primary electron acceptor
c. endergonic as the P700+ chlorophyll a molecule is less electronegative than the primary electron acceptor
d. endergonic as the P700+ chlorophyll a molecule is more electronegative than the primary electron acceptor
exergonic as the P700+ chlorophyll a molecule is more electronegative than the primary electron acceptor
Where are the proteins of the electron transport chain located?
a. cytosol
b. mitochondrial outer membrane
c. mitochondrial inner membrane
d. mitochondrial intermembrane space
mitochondrial inner membrane
Where are the molecules of the electron transport chain found in plant cells?
a. thylakoid membranes of chloroplasts and inner membranes of mitochondria
b. stroma of chloroplasts
c. thylakoid membrane only
d. inner membrane of mitochondria only
thylakoid membranes of chloroplasts and inner membranes of mitochondria
Which process is most directly driven by light energy?
a. creation of a pH gradient by pumping protons across the thylakoid membrane
b. ATP synthesis
c. reduction of NADP+ molecules
d. removal of electrons from chlorophyll molecules
removal of electrons from chlorophyll molecules
It is possible to prepare vesicles from portions of the inner mitochondrial membrane. Which one of the following processes could still be carried on by this isolated inner membrane?
a. reduction of NAD+
b. oxidative phosphorylation
c. glycolysis and fermentation
d. both the citric acid cycle and oxidative phosphorylation
oxidative phosphorylation
Which of the following statements about proton gradients is FALSE?
a. Proton gradients cannot be used to do work
b. A proton gradient is present when the concentration of protons is higher on one side of a biological membrane than on the other side
c. Proton gradients contain potential energy
d. A proton gradient is present when the concentration of hydrogen ions is higher on one side of a biological membrane than on the other side
proton gradients cannot be used to do work
Phosphofructokinase is an allosteric enzyme that catalyzes the conversion of fructose 6-phosphate to fructose 1,6-bisphosphate, an early step of glycolysis. In the presence of oxygen, an increase in the amount of ATP in a cell would be expected to
a. inhibit the enzyme and thus slow the rates of glycolysis and the citric acid cycle.
b. inhibit the enzyme and thus increase the rates of glycolysis and the citric acid cycle.
c. activate the enzyme and thus slow the rates of glycolysis and the citric acid cycle.
d. activate the enzyme and increase the rates of glycolysis and the citric acid cycle.
inhibit the enzyme and thus slow the rates of glycolysis and the citric acid cycle
The ATP made during glycolysis is generated by
a. photophosphorylation.
b. substrate-level phosphorylation.
c. electron transport.
d. chemiosmotic phosphorylation.
substrate-level phosphorylation
The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the
a. flow of electrons down the electron transport chain.
b. oxidation of glucose and other organic compounds.
c. affinity of oxygen for electrons.
d. H+ concentration across the membrane holding ATP synthase.
H+ concentration across the membrane holding ATP synthase
During the metabolic processes of cell respiration and photosynthesis, the complexes that are components of the electron transport chain
a. both oxidize and reduce during electron transport
b. act as reducing agents
c. act as oxidizing agents
d. donate electrons
both oxidize and reduce during electron transport
Why does the oxidation of organic compounds by molecular oxygen to produce CO2 and water release free energy?
a. The covalent bonds in organic molecules and molecular oxygen have more kinetic energy than the covalent bonds in water and carbon dioxide.
b. The electrons have a higher potential energy when associated with water and CO2 than they do in organic compounds.
c. The oxidation of organic compounds can be used to make ATP.
d. Electrons are being moved from atoms that have a lower affinity for electrons (such as C) to atoms with a higher affinity for electrons (such as O).
electrons are being moved from atoms that have a lower affinity for electrons to atoms with a higher affinity for electrons
A mutation in yeast makes it unable to convert pyruvate to ethanol. How will this mutation affect these yeast cells?
a. The mutant yeast will grow anaerobically only when given glucose.
b. The mutant yeast will die because they cannot regenerate NAD+ from NAD.
c. The mutant yeast will be unable to metabolize glucose.
d. The mutant yeast will be unable to grow anaerobically.
the mutant yeast will be unable to grow anaerobically
When oxygen is released as a result of photosynthesis, it is a direct by-product of
a. chemiosmosis.
b. reducing NADP+.
c. the electron transfer system of photosystem I.
d. splitting water molecules.
splitting water molecules
To sustain high rates of glycolysis under anaerobic conditions, cells require
a. regeneration of NAD+
b. all of these answers are correct
c. oxidative phosphorylation of ATP.
d. regeneration of NADH
regeneration of NAD+
During photosynthesis, energy from light is first captured by
a. a primary electron donor
b. a reaction-center complex
c. a pigment molecule in a light harvesting complex
d. a primary electron acceptor
a pigment molecule in a light harvesting complex
Where does the Calvin cycle (i.e.the dark reactions of photosynthesis) take place?
a. thylakoid membrane
b. outer membrane of the chloroplast
c. interior of the thylakoid (thylakoid space)
d. stroma of the chloroplast
stroma of the chloroplast
Reduction of NADP+ occurs during
a. both photosynthesis and respiration.
b. photorespiration.
c. respiration.
d. photosynthesis.
photosynthesis
In the thylakoid membranes, what is the main role of the pigment molecules in the light-harvesting complexes?
a. Synthesize ATP from ADP and Pi
b. Transfer electrons to ferredoxin and then NADPH
c. Split water and release oxygen
d. Harvest photons and transfer light energy to the reaction-center chlorophyll
harvest photons and transfer light energy to the reaction-center chlorophyll
Which of the following statements describes NAD+?
a. NAD+ can donate electrons for use in oxidative phosphorylation.
b. In the absence of NAD+, glycolysis can still function.
c. NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric acid cycle.
d. NAD+ has more chemical energy than NADH.
NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric acid cycle
Generation of proton gradients across membranes occurs during
a. photosynthesis.
b. both photosynthesis and respiration.
c. neither photosynthesis nor respiration.
d. respiration.
both photosynthesis and respiration
What does the chemiosmotic process in chloroplasts involve?
a. reduction of water to produce ATP energy
b. movement of water by osmosis into the thylakoid space from the stroma
c. formation of glucose, using carbon dioxide, NADPH, and ATP
d. establishment of a proton gradient across the thylakoid membrane
establishment of a proton gradient across the thylakoid membrane
When a pigment molecule in a light-harvesting complex absorbs the energy from a photon of light, an electron in the pigment molecule becomes "excited". What does this mean?
a. The electron has acquired a greater charge.
b. The electron has acquired greater speed, meaning greater kinetic energy.
c. The electron has achieved a higher-energy state, meaning that it is located further from the nucleus.
d. The electron has achieved a higher-energy state, meaning that it is located closer to the nucleus.
the electron has achieved a higher-energy state, meaning that it is located further from the nucleus
The ATP made during fermentation is generated by which of the following?
a. oxidative phosphorylation
b. chemiosmosis
c. aerobic respiration
d. substrate-level phosphorylation
substrate-level phosphorylation
The reactions that produce NADPH occur in
a. neither the light reactions nor the Calvin cycle.
b. the light reactions alone.
c. the Calvin cycle alone.
d. both the light reactions and the Calvin cycle.
the light reactions alone
What is the oxidizing agent in the following reaction?
Pyruvate + NADH + H+ → Lactate + NAD+
a. pyruvate
b. NADH
c. NAD+
d. lactate
pyruvate
Pyruvate is transported into mitochondria by
a. a symporter that transports pyruvate up its concentration gradient while transporting protons down their electrochemical gradient.
b. a symporter that transports pyruvate down its concentration gradient while transporting protons up their electrochemical gradient.
c. an antiporter that transports pyruvate up its concentration gradient while transporting protons down their electrochemical gradient.
d. an antiporter that transports pyruvate down its concentration gradient while transporting protons up their electrochemical gradient.
a symporter that transports pyruvate up its concentration gradient while transporting protons down their electrochemical gradient
Most of the energy released during cellular respiration ends up:
a. being used to make lipids
b. being lost as heat
c. being used to make NADH
d. being used to make ATP
being lost as heat
In the process known as "substrate-level phosphorylation",
a. a phosphate group is transferred from a substrate molecule to ADP
b. all of these answers are correct
c. a phosphate group is transferred from ATP to a substrate molecule
d. a phosphate group is transferred from a substrate molecule to ATP
a phosphate group is transferred from a substrate molecule to ADP
When oxygen is released as a result of photosynthesis, it is a direct by-product of
a. reducing NADP+.
b. the electron transfer system of photosystem I.
c. splitting water molecules.
d. chemiosmosis.
splitting water molecules
The energy from an excited electron can be passed from one pigment molecule to another via a process known as
a. photonic energy transfer
b. light conductance
c. resonance energy transfer
d. photon energy conductance
resonance energy transfer
When comparing electronegativities,
a. oxygen is more electronegative than all of the components of the electron transport chain
b. oxygen is more electronegative than NADH
c. all of these answers are correct
d. oxygen is more electronegative than FADH2
all of these answers are correct
In a plant leaf, the reactions that produce NADH (NADH, not NADPH) occur in
a. the Calvin cycle alone.
b. neither the light reactions nor the Calvin cycle.
c. both the light reactions and the Calvin cycle.
d. the light reactions alone.
neither the light reactions nor the calvin cycle
Which of the following are products of the light reactions of photosynthesis that are subsequently utilized in the Calvin cycle?
a. H2O and O2
b. CO2 and glucose
c. ADP, Pi and NADP+
d. ATP and NADPH
ATP and NADPH
A molecule that is phosphorylated
a. has a decreased chemical reactivity, it is less likely to provide energy for cellular work.
b. has less energy than before its phosphorylation and therefore less energy for cellular work.
c. is unchanged in its capacity to do cellular work.
d. has an increased chemical reactivity, it is primed to do cellular work.
has an increased chemical reactivity, it is primed to do cellular work
Substrate-level phosphorylation accounts for approximately what percentage of the ATP formed directly by the reactions of glycolysis?
a. 10%
b. 100%
c. 38%
d. 0%
100%
Reactions that require CO2 take place in
a. neither the light reactions nor the Calvin cycle.
b. both the light reactions and the Calvin cycle.
c. the Calvin cycle alone.
d. the light reactions alone.
the calvin cycle alone
In a mitochondrion, if the matrix ATP concentration is high, and the intermembrane space proton concentration is too low to generate sufficient proton-motive force, then
a. ATP synthase will increase the rate of ATP synthesis.
b. ATP synthase will stop working.
c. ATP synthase will hydrolyze ATP and pump protons into the intermembrane space.
d. ATP synthase will hydrolyze ATP and pump protons into the matrix.
ATP synthase will hydrolyze ATP and pump protons into the intermembrane space
The free energy for the oxidation of glucose to CO2 and water is -686 kcal/mol and the free energy for the reduction of NAD+ to NADH is +53 kcal/mol. What is the main reason that only two molecules of NADH formed during glycolysis when it appears that as many as a dozen could be formed?
a. Glycolysis consists of many enzymatic reactions, each of which extracts some energy from the glucose molecule.
b. Most of the free energy available from the oxidation of glucose is used in the production of ATP in glycolysis.
c. Most of the free energy available from the oxidation of glucose remains in pyruvate, one of the products of glycolysis.
d. Glycolysis is a very inefficient reaction, with much of the energy of glucose released as heat.
most of the free energy available from the oxidation of glucose remains in pyruvate, one of the products of glycolysis
During glycolysis, when each molecule of glucose is catabolized to two molecules of pyruvate, most of the potential energy contained in glucose is
a. retained in the two pyruvates.
b. transferred directly to ATP.
c. stored in the NADH produced.
d. transferred to ADP, forming ATP.
retained in the two pyruvates
In chemiosmotic phosphorylation, what is the most direct source of energy that is used to convert ADP + inorganic phosphate to ATP?
a. energy released as electrons flow through the electron transport system
b. No external source of energy is required because the reaction is exergonic.
c. energy released from movement of protons through ATP synthase, against the electrochemical gradient
d. energy released from movement of protons through ATP synthase, down the electrochemical gradient
energy released from movement of protons through ATP synthase, down the electrochemical gradient
In the reaction shown below

CH4 + 2 O2 → CO2 + energy + 2 H2O

a. CH4 and O2 are the reducing agents
b. CH4 is the reducing agent and O2 is the oxidizing agent
c. CH4 and O2 are the oxidizing agents
d. CH4 is the oxidizing agent and O2 is the reducing agent
CH4 is the reducing agent and O2 is the oxidizing agent
Inside an active mitochondrion, most electrons follow which pathway?
a. electron transport chain → citric acid cycle → ATP → oxygen
b. pyruvate → citric acid cycle → ATP → NADH → oxygen
c. glycolysis → NADH → oxidative phosphorylation → ATP → oxygen
d. citric acid cycle → NADH → electron transport chain → oxygen
citric acid cycle -> NADH -> electron transport chain -> oxygen