PROCTOR VERSION
2.5 B: Energy Structure of Cells Quiz
1.
A planarian has a mutation that affects mitochondria. The planarian moves slower and has a
slower rate of growth and reproduction than a normal planarian. A mitochondrion from a normal
planarian (planarian X) and a mitochondrion from the planarian with the mutation (planarian Y)
are shown below.
Which statement best explains why planarian Y moves, grows, and reproduces at a slower rate
than planarian X?
(A) The mitochondrion from planarian Y does not have a large enough surface area to absorb
food and oxygen to produce ATP.
Distractor Rationale:
This answer suggests the student may understand that the inner mitochondrial membrane of
planarian Y has less surface area, but does not understand that the inner mitochondrial
membrane does not directly absorb food, or that the rate at which oxygen is used is reduced
because the reduced surface area of the inner membrane reduces the number of places
where the reactions that produce ATP can occur.
(B) The mitochondrion from planarian Y does not have enough space in the matrix to store
enzymes needed to generate ATP through the oxidation of organic molecules.
Page 1 of 6
PROCTOR VERSION
2.5 B: Energy Structure of Cells Quiz
Distractor Rationale:
This answer suggests the student may understand that organic molecules are oxidized in
the mitochondrial matrix, but does not understand that the space inside the matrix is larger
in planarian Y, and that the reduced surface area of the inner membrane means there are
fewer places where the reactions needed for ATP production can occur.
(C) The mitochondrion from planarian Y does not have a large enough surface area to hold
electron-transferring proteins and is unable to adequately oxidize NADH and FADH2 to
generate enough ATP.
Rationale:
This answer suggests the student understands that the folding of the inner mitochondrial
membrane increases its surface area, which allows more ions to be pumped into the
intermembrane space and produce an electrochemical gradient, and that this allows for
more rapid production of ATP during cellular respiration because there is more surface on
which reactions can occur.
(D) The mitochondrion from planarian Y does not have the ability to pump H+ into the
intermembrane space, and is unable to produce ATP through chemiosmosis.
Distractor Rationale:
This answer suggests the student may understand that H+ storage is needed to generate
ATP and that ATP is produced through chemiosmosis, but does not understand that only
the rate at which H+ is pumped into the intermembrane space is affected, or that the
reduced surface area of the inner membrane means that there are fewer places where the
reactions needed for ATP production can occur.
Aligned to: LO 2.5 CA 2.5: Explain Energy Use, Storage & Capture
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PROCTOR VERSION
2.5 B: Energy Structure of Cells Quiz
2.
Cyanide is introduced into a culture of cells and is observed binding to a mitochondrion, as
shown in the diagram below.
The following observations are made:
• Cyanide binds to and inhibits an enzyme in the inner mitochondrial membrane.
• There is a decrease in water production in the inner mitochondrial membrane.
• Cyanide causes a build-up of electrons in the form of NADH.
Which statement best explains how cyanide disrupts cellular processes?
(A) Cyanide prevents organic molecules from entering the mitochondrion.
Distractor Rationale:
This answer suggests the student may understand that organic molecules (pyruvate) must
enter the mitochondrion, but does not understand that cyanide primarily disrupts the
electron transport chain by binding to enzymes that accept or donate electrons along the
electron transport chain.
(B) Cyanide prevents enzymes from splitting glucose in substrate-level phosphorylation.
Distractor Rationale:
This answer suggests the student may understand that the splitting of glucose in substratelevel phosphorylation involves enzymes and produces energy-rich molecules that drive the
electron transport chain, but does not understand that the splitting of glucose occurs
outside the mitochondrion in the cytosol and is not affected by the presence of cyanide.
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PROCTOR VERSION
2.5 B: Energy Structure of Cells Quiz
(C) Cyanide prevents the production of carbon dioxide by binding to the enzymes involved in the
citric acid cycle.
Distractor Rationale:
This answer suggests the student may understand that carbon dioxide is produced during
the citric acid cycle, but does not understand that cyanide primarily disrupts an enzyme in
the electron transport chain from accepting or donating electrons and does not disrupt the
citric acid cycle directly.
(D) Cyanide prevents the oxidation of energy-rich molecules by binding to enzymes that
facilitate movement of the electrons in the electron transport chain.
Rationale:
This answer suggests the student understands that the location of the electron transport
chain is in the inner mitochondrial membrane, and that cyanide binds to enzymes in the
electron transport chain, preventing them from accepting and donating electrons in the
electron transport chain, which then prevents the formation of an electrochemical gradient
needed to power the production of ATP via chemiosmosis.
Aligned to: LO 2.5 CA 2.5: Explain Energy Use, Storage & Capture
3.
The diagram below shows the pathway for the movement of electrons in a mitochondrion.
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PROCTOR VERSION
2.5 B: Energy Structure of Cells Quiz
Which statement describes the process in chloroplasts that is most similar to the process shown
in the diagram?
(A) The reduction of carbon dioxide into 3-carbon sugars in the stroma during the Calvin cycle
Distractor Rationale:
This answer suggests the student may understand that the reduction of carbon dioxide to 3carbon sugars involves the transfer of electrons, but does not understand that electrons
are not transferred in a way that is similar to the movement of electrons down an
electrochemical gradient in the electron transport chain.
(B) The excitation of electrons in photosystem II on the thylakoid membrane during the lightdependent reaction
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PROCTOR VERSION
2.5 B: Energy Structure of Cells Quiz
Distractor Rationale:
This answer suggests the student may understand that electrons are excited by light in
photosystem II, but does not understand that electrons are excited to higher energy levels
in photosystem II, rather than moving to lower energy levels as they move through the
electron transport chain.
(C) The movement of hydrogen ions from a high concentration inside of the thylakoid space to
the stroma via chemiosmosis
Distractor Rationale:
This answer suggests the student may understand that hydrogen ions move from the
thylakoid space to the stroma during chemiosmosis in chloroplasts, but does not
understand that the movement of hydrogen ions in the diagram is from regions of low
concentration to regions of high concentration (the electron transport chain) to produce the
electrochemical gradient that is then used to drive the production of ATP (chemiosmosis).
(D) The oxidation of proteins on the thylakoid membrane during noncyclic photophosphorylation
to create an electrochemical gradient
Rationale:
This answer suggests the student understands that the electron transport chain on the
thylakoid membrane is similar to the electron transport chain on the inner mitochondrial
membrane and that the energy released by the transfer of electrons through the electron
transport chain via redox reactions is used to pump protons across a membrane, which
produces an electrochemical gradient that provides energy for the production of ATP
(chemiosmosis).
Aligned to: LO 2.5 CA 2.5: Explain Energy Use, Storage & Capture
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