D103 Midterm Exam Newest 2026 Questions and
Correct Detailed Answers Already Graded A+
Which of the following statements is most correct?
The electron transport chain -
A: generates a pH gradient that reduces O2 to H2O
B: generates a proton gradient across the outer mito membrane
C: generates a proton gradient across the inner mito membrane
D: uses the energy stored in high energy electron carriers to synthesize ATP
E: establishes a membrane potential across the outer mito membrane -
CORRECT ANSWER-generates a proton gradient across the inner mito
membrane
Which of the following statements best describes properties of mitochondrial
DNA?
A: It is circular
B: It contains more nucleotides than nuclear DNA
C: It encodes all proteins found in mitochondria
D: It is transported into the cytosol for transcription and translation
E: It is replicated in parallel with nuclear DNA - CORRECT ANSWER-It is circular
,Describe pedigrees of mito mutations - CORRECT ANSWER-If a female has
trait, all of her offspring will be affected in some degree based on # mutated mito
they inherit
If male has trait and his female partner doesn't have trait, their offspring won't be
affected
What is the role of cardiolipin in the inner mitochondrial membrane? -
CORRECT ANSWER-it limits the permeability of the membrane
Which of the following statements best describes a factor(s) that is required for
efficient ATP synthesis by mitochondria?
A: An ATP-driven proton pump in the inner mito membrane.
B: An electron gradient across the inner mito membrane.
C: The Na+/K+ pump, which establishes an electrochemical gradient for Na+, that
then drives proton movement.
D: A proton gradient and membrane potential across the outer mito membrane.
E: A steep electrochemical gradient for protons, made up of a pH gradient and a
membrane potential across the inner mito membrane - CORRECT ANSWER-A
steep electrochemical gradient for protons, made up of a pH gradient and a
membrane potential across the inner mito membrane
,Understand the typical characteristics of phospholipids in a membrane (head, tail,
membrane) - CORRECT ANSWER-Polar hydrophilic heads/nonpolar
hydrophobic tail
Tail = long fatty acid chain; bent (unsaturated) double bonds make more space for
membrane and curvature for membrane
Be able to explain what is membrane fluidity And how it is regulated (3 factors) -
CORRECT ANSWER-Fluidity increases w/ increased temp, decreased saturation
(more double bonds), decreased length, decreased cholesterol
Differences between phospholipids? - CORRECT ANSWER-All phospholipids
are amphipathic
Understand how proteins can associate with a lipid bilayer - CORRECT
ANSWER-transmembrane, lipid-anchored, peripheral
Be able to analyze hydrophobicity plots to predict the transmembrane domain for
a transmembrane protein - CORRECT ANSWER-Membrane-embedded region
on TM protein = 20-25 hydrophobic a.a.; hydropathy plot shows energy needed to
transfer a.a. from nonpolar solvent to H2O; transmembrane regions >0 and >20
a.a.
, Hot springs such as those found in Yellowstone National Park are rich in
thermophile bacteria. If you isolated and analyzed the phospholipids (PLs) of
these bacteria, what would you predict to see? (saturated fatty acid tails,
unsaturated fatty acid tails, glycerol backbone, short fatty acid tails) - CORRECT
ANSWER-high percentage of PLs with saturated fatty acid tails
Why does Ketoconazole work as an anti-fungal? Ketoconazole - interferes with
the synthesis of ergosterol (a cholesterol-like molecule) in fungi - CORRECT
ANSWER-It kills by increasing the fluidity of the fungal PM
1. Which factors are likely to lead to a decrease in membrane fluidity?
A: An increase in the number of unsaturated bonds in the hydrophobic tail of
phospholipids
B: An increase in the activity of a transmembrane protein
C: A change in the molar ratio of PC to PE
D: An increase in the number of phospholipids with long hydrophobic tails -
CORRECT ANSWER-An increase in the number of phospholipids with long
hydrophobic tails
2. Which of the following organisms is most likely to have the highest percentage
of unsaturated fatty acid chains in their membranes? (hint: organisms try to
preserve the balance for their membrane dynamics)
Correct Detailed Answers Already Graded A+
Which of the following statements is most correct?
The electron transport chain -
A: generates a pH gradient that reduces O2 to H2O
B: generates a proton gradient across the outer mito membrane
C: generates a proton gradient across the inner mito membrane
D: uses the energy stored in high energy electron carriers to synthesize ATP
E: establishes a membrane potential across the outer mito membrane -
CORRECT ANSWER-generates a proton gradient across the inner mito
membrane
Which of the following statements best describes properties of mitochondrial
DNA?
A: It is circular
B: It contains more nucleotides than nuclear DNA
C: It encodes all proteins found in mitochondria
D: It is transported into the cytosol for transcription and translation
E: It is replicated in parallel with nuclear DNA - CORRECT ANSWER-It is circular
,Describe pedigrees of mito mutations - CORRECT ANSWER-If a female has
trait, all of her offspring will be affected in some degree based on # mutated mito
they inherit
If male has trait and his female partner doesn't have trait, their offspring won't be
affected
What is the role of cardiolipin in the inner mitochondrial membrane? -
CORRECT ANSWER-it limits the permeability of the membrane
Which of the following statements best describes a factor(s) that is required for
efficient ATP synthesis by mitochondria?
A: An ATP-driven proton pump in the inner mito membrane.
B: An electron gradient across the inner mito membrane.
C: The Na+/K+ pump, which establishes an electrochemical gradient for Na+, that
then drives proton movement.
D: A proton gradient and membrane potential across the outer mito membrane.
E: A steep electrochemical gradient for protons, made up of a pH gradient and a
membrane potential across the inner mito membrane - CORRECT ANSWER-A
steep electrochemical gradient for protons, made up of a pH gradient and a
membrane potential across the inner mito membrane
,Understand the typical characteristics of phospholipids in a membrane (head, tail,
membrane) - CORRECT ANSWER-Polar hydrophilic heads/nonpolar
hydrophobic tail
Tail = long fatty acid chain; bent (unsaturated) double bonds make more space for
membrane and curvature for membrane
Be able to explain what is membrane fluidity And how it is regulated (3 factors) -
CORRECT ANSWER-Fluidity increases w/ increased temp, decreased saturation
(more double bonds), decreased length, decreased cholesterol
Differences between phospholipids? - CORRECT ANSWER-All phospholipids
are amphipathic
Understand how proteins can associate with a lipid bilayer - CORRECT
ANSWER-transmembrane, lipid-anchored, peripheral
Be able to analyze hydrophobicity plots to predict the transmembrane domain for
a transmembrane protein - CORRECT ANSWER-Membrane-embedded region
on TM protein = 20-25 hydrophobic a.a.; hydropathy plot shows energy needed to
transfer a.a. from nonpolar solvent to H2O; transmembrane regions >0 and >20
a.a.
, Hot springs such as those found in Yellowstone National Park are rich in
thermophile bacteria. If you isolated and analyzed the phospholipids (PLs) of
these bacteria, what would you predict to see? (saturated fatty acid tails,
unsaturated fatty acid tails, glycerol backbone, short fatty acid tails) - CORRECT
ANSWER-high percentage of PLs with saturated fatty acid tails
Why does Ketoconazole work as an anti-fungal? Ketoconazole - interferes with
the synthesis of ergosterol (a cholesterol-like molecule) in fungi - CORRECT
ANSWER-It kills by increasing the fluidity of the fungal PM
1. Which factors are likely to lead to a decrease in membrane fluidity?
A: An increase in the number of unsaturated bonds in the hydrophobic tail of
phospholipids
B: An increase in the activity of a transmembrane protein
C: A change in the molar ratio of PC to PE
D: An increase in the number of phospholipids with long hydrophobic tails -
CORRECT ANSWER-An increase in the number of phospholipids with long
hydrophobic tails
2. Which of the following organisms is most likely to have the highest percentage
of unsaturated fatty acid chains in their membranes? (hint: organisms try to
preserve the balance for their membrane dynamics)
