, CHEM 210 | Module 8 | Original Biochemistry Practice
CHEM 210 Module 8 Exam | Biochemistry | Portage
| Q & A | 26/27 Actual (PDF)
1. A hepatocyte is processing amino-acid nitrogen and the step involving ornithine
transcarbamylasebecomes important. Which interpretation is most accurate?
A) OTC transfers electrons to oxygen
B) OTC forms urea directly from arginine
C) Ornithine transcarbamylase transfers the carbamoyl group to ornithine to form citrulline in the
mitochondrion.
D) OTC acts only in the cytosol
Correct Answer: Ornithine transcarbamylase transfers the carbamoyl group to ornithine to form citrulline in
the mitochondrion.
Rationale: Ornithine transcarbamylase transfers the carbamoyl group to ornithine to form citrulline in the
mitochondrion. This helps explain how nitrogen is transferred, compartmentalized, converted to urea, and linked
with central carbon metabolism.
2. Which statement best describes respiratory control in CHEM 210 Module 8?
A) Respiratory Control occurs without any dependence on enzymes, cellular compartment, or molecular
carriers.
B) Respiratory Control has the opposite biochemical role from the process described.
C) Respiratory Control is unrelated to nitrogen handling or mitochondrial ATP production.
D) Electron transport and oxidative phosphorylation accelerate when ADP and substrate are available and
slow whenATP demand is low.
Correct Answer: Electron transport and oxidative phosphorylation accelerate when ADP and substrate are
available and slow when ATP demand is low.
Rationale: Electron transport and oxidative phosphorylation accelerate when ADP and substrate are available and
slow when ATP demand is low. This concept is central to Portage Module 8's emphasis on nitrogen handling, the
urea cycle, mitochondrial electron transport, chemiosmosis, and ATP production.
3. A mitochondrion is producing ATP aerobically and the role of Complex III must be identified.
Whichstatement is most accurate?
A) Complex III transfers electrons from reduced coenzyme Q to cytochrome c and contributes to proton
translocation.
B) Complex III receives electrons directly from oxygen
C) Complex III transfers electrons to NADH
D) Complex III is located in the cytosol
Correct Answer: Complex III transfers electrons from reduced coenzyme Q to cytochrome c and contributes to
proton translocation.
Rationale: Complex III transfers electrons from reduced coenzyme Q to cytochrome c and contributes to proton
translocation. This follows the chemiosmotic model in which electron flow establishes a proton gradient that is then
used by ATP synthase.
4. A hepatocyte is processing amino-acid nitrogen and the step involving glutamate role
becomesimportant. Which interpretation is most accurate?
Page 2
, CHEM 210 | Module 8 | Original Biochemistry Practice
A) Glutamate Role is unrelated to nitrogen handling or mitochondrial ATP production.
B) Glutamate acts as a major collector and donor of amino groups in amino-acid metabolism.
C) Glutamate Role has the opposite biochemical role from the process described.
D) Glutamate Role occurs without any dependence on enzymes, cellular compartment, or molecular
carriers.
Correct Answer: Glutamate acts as a major collector and donor of amino groups in amino-acid metabolism.
Rationale: Glutamate acts as a major collector and donor of amino groups in amino-acid metabolism. This helps
explain how nitrogen is transferred, compartmentalized, converted to urea, and linked with central carbon
metabolism.
5. Which statement best describes urea carbon in CHEM 210 Module 8?
A) Urea Carbon is unrelated to nitrogen handling or mitochondrial ATP production.
B) The carbonyl carbon of urea originates from bicarbonate.
C) Urea Carbon has the opposite biochemical role from the process described.
D) Urea Carbon occurs without any dependence on enzymes, cellular compartment, or molecular carriers.
Correct Answer: The carbonyl carbon of urea originates from bicarbonate.
Rationale: The carbonyl carbon of urea originates from bicarbonate. This concept is central to Portage Module 8's
emphasis on nitrogen handling, the urea cycle, mitochondrial electron transport, chemiosmosis, and ATP
production.
6. Which statement best describes proton motive force in CHEM 210 Module 8?
A) The proton motive force combines the membrane potential and proton concentration gradient across the
innermitochondrial membrane.
B) Proton Motive Force occurs without any dependence on enzymes, cellular compartment, or molecular
carriers.
C) Proton Motive Force has the opposite biochemical role from the process described.
D) Proton Motive Force is unrelated to nitrogen handling or mitochondrial ATP production.
Correct Answer: The proton motive force combines the membrane potential and proton concentration gradient
across the inner mitochondrial membrane.
Rationale: The proton motive force combines the membrane potential and proton concentration gradient across the
inner mitochondrial membrane. This concept is central to Portage Module 8's emphasis on nitrogen handling, the
urea cycle, mitochondrial electron transport, chemiosmosis, and ATP production.
7. A mitochondrion is producing ATP aerobically and the role of Complex I must be identified.
Whichstatement is most accurate?
A) Complex I transfers electrons directly from cytochrome c to oxygen
B) Complex I is ATP synthase
C) Complex I does not interact with NADH
D) Complex I transfers electrons from NADH to coenzyme Q and pumps protons across the inner
mitochondrialmembrane.
Correct Answer: Complex I transfers electrons from NADH to coenzyme Q and pumps protons across the inner
mitochondrial membrane.
Rationale: Complex I transfers electrons from NADH to coenzyme Q and pumps protons across the inner
mitochondrial membrane. This follows the chemiosmotic model in which electron flow establishes a proton gradient
that is then used by ATP synthase.
Page 3
CHEM 210 Module 8 Exam | Biochemistry | Portage
| Q & A | 26/27 Actual (PDF)
1. A hepatocyte is processing amino-acid nitrogen and the step involving ornithine
transcarbamylasebecomes important. Which interpretation is most accurate?
A) OTC transfers electrons to oxygen
B) OTC forms urea directly from arginine
C) Ornithine transcarbamylase transfers the carbamoyl group to ornithine to form citrulline in the
mitochondrion.
D) OTC acts only in the cytosol
Correct Answer: Ornithine transcarbamylase transfers the carbamoyl group to ornithine to form citrulline in
the mitochondrion.
Rationale: Ornithine transcarbamylase transfers the carbamoyl group to ornithine to form citrulline in the
mitochondrion. This helps explain how nitrogen is transferred, compartmentalized, converted to urea, and linked
with central carbon metabolism.
2. Which statement best describes respiratory control in CHEM 210 Module 8?
A) Respiratory Control occurs without any dependence on enzymes, cellular compartment, or molecular
carriers.
B) Respiratory Control has the opposite biochemical role from the process described.
C) Respiratory Control is unrelated to nitrogen handling or mitochondrial ATP production.
D) Electron transport and oxidative phosphorylation accelerate when ADP and substrate are available and
slow whenATP demand is low.
Correct Answer: Electron transport and oxidative phosphorylation accelerate when ADP and substrate are
available and slow when ATP demand is low.
Rationale: Electron transport and oxidative phosphorylation accelerate when ADP and substrate are available and
slow when ATP demand is low. This concept is central to Portage Module 8's emphasis on nitrogen handling, the
urea cycle, mitochondrial electron transport, chemiosmosis, and ATP production.
3. A mitochondrion is producing ATP aerobically and the role of Complex III must be identified.
Whichstatement is most accurate?
A) Complex III transfers electrons from reduced coenzyme Q to cytochrome c and contributes to proton
translocation.
B) Complex III receives electrons directly from oxygen
C) Complex III transfers electrons to NADH
D) Complex III is located in the cytosol
Correct Answer: Complex III transfers electrons from reduced coenzyme Q to cytochrome c and contributes to
proton translocation.
Rationale: Complex III transfers electrons from reduced coenzyme Q to cytochrome c and contributes to proton
translocation. This follows the chemiosmotic model in which electron flow establishes a proton gradient that is then
used by ATP synthase.
4. A hepatocyte is processing amino-acid nitrogen and the step involving glutamate role
becomesimportant. Which interpretation is most accurate?
Page 2
, CHEM 210 | Module 8 | Original Biochemistry Practice
A) Glutamate Role is unrelated to nitrogen handling or mitochondrial ATP production.
B) Glutamate acts as a major collector and donor of amino groups in amino-acid metabolism.
C) Glutamate Role has the opposite biochemical role from the process described.
D) Glutamate Role occurs without any dependence on enzymes, cellular compartment, or molecular
carriers.
Correct Answer: Glutamate acts as a major collector and donor of amino groups in amino-acid metabolism.
Rationale: Glutamate acts as a major collector and donor of amino groups in amino-acid metabolism. This helps
explain how nitrogen is transferred, compartmentalized, converted to urea, and linked with central carbon
metabolism.
5. Which statement best describes urea carbon in CHEM 210 Module 8?
A) Urea Carbon is unrelated to nitrogen handling or mitochondrial ATP production.
B) The carbonyl carbon of urea originates from bicarbonate.
C) Urea Carbon has the opposite biochemical role from the process described.
D) Urea Carbon occurs without any dependence on enzymes, cellular compartment, or molecular carriers.
Correct Answer: The carbonyl carbon of urea originates from bicarbonate.
Rationale: The carbonyl carbon of urea originates from bicarbonate. This concept is central to Portage Module 8's
emphasis on nitrogen handling, the urea cycle, mitochondrial electron transport, chemiosmosis, and ATP
production.
6. Which statement best describes proton motive force in CHEM 210 Module 8?
A) The proton motive force combines the membrane potential and proton concentration gradient across the
innermitochondrial membrane.
B) Proton Motive Force occurs without any dependence on enzymes, cellular compartment, or molecular
carriers.
C) Proton Motive Force has the opposite biochemical role from the process described.
D) Proton Motive Force is unrelated to nitrogen handling or mitochondrial ATP production.
Correct Answer: The proton motive force combines the membrane potential and proton concentration gradient
across the inner mitochondrial membrane.
Rationale: The proton motive force combines the membrane potential and proton concentration gradient across the
inner mitochondrial membrane. This concept is central to Portage Module 8's emphasis on nitrogen handling, the
urea cycle, mitochondrial electron transport, chemiosmosis, and ATP production.
7. A mitochondrion is producing ATP aerobically and the role of Complex I must be identified.
Whichstatement is most accurate?
A) Complex I transfers electrons directly from cytochrome c to oxygen
B) Complex I is ATP synthase
C) Complex I does not interact with NADH
D) Complex I transfers electrons from NADH to coenzyme Q and pumps protons across the inner
mitochondrialmembrane.
Correct Answer: Complex I transfers electrons from NADH to coenzyme Q and pumps protons across the inner
mitochondrial membrane.
Rationale: Complex I transfers electrons from NADH to coenzyme Q and pumps protons across the inner
mitochondrial membrane. This follows the chemiosmotic model in which electron flow establishes a proton gradient
that is then used by ATP synthase.
Page 3
