PCOL 832 EXAM 2 ALL LECTURE
QUESTIONS AND ANSWERS
I: Molecular motors driven by ATP hydrolysis
II: Performing anabolic biochemical work example: glycogen biosynthesis
III: ATP-dependent transmembrane transport: the gastric proton pump as drug target
IV: Transmembrane transport: a plasma membrane ATPase as drug target
V: ATP-dependent transmembrane transport: Sodium:serotonin symporter - Correct
Answers -What are the 5 uses for ATP?
A proton pump inhibitor (PPI) acting by irreversibly blocking the H+/K+ ATPase (proton
pump) of the gastric parietal cell.
ex.) omeprazole - Correct Answers -How does a proton pump inhibitor (PPI) work?
Digoxin (digitalis) works by inhibiting heart muscle cell sodium- potassium ATPase. This
results in an increased intracellular concentration of sodium, which in turn increases
intracellular calcium by passively decreasing the action of the sodium-calcium
exchanger (antiporter) in the sarcolemma. The increased intracellular calcium gives a
positive inotropic effect (increased heart contractility). - Correct Answers -How does
digoxin work?
SERT is the target of many antidepressant medications, including those of the selective
serotonin reuptake inhibitor (SSRI) class: example fluoxetine (ProzacTM)
The serotonin transporter (SERT) is an integral membrane protein that transports the
neurotransmitter serotonin from synaptic spaces into presynaptic neurons. It is a
member of the sodium:neurotransmitter symporter family. - Correct Answers -What is
the target of many antidepressant medications?
change in free energy
-energy available to do work,
-approaches zero as a reaction proceeds to equilibrium,
-predicts whether a reaction is favorable - Correct Answers -What is the ∆G in gibbs
free energy?
change in enthalpy
-heat released or absorbed during a reaction
-does not predict whether a reaction is favorable - Correct Answers -What is the ∆H in
gibbs free energy?
,change in entropy
-measure of randomness
-does not predict whether a reaction is favorable - Correct Answers -What is the ∆S in
gibbs free energy?
The Gibbs Free Energy provides a way to determine if a reaction is favorable or
favorable in the direction written under a given pressure and temperature. - Correct
Answers -What is the equation for gibbs free energy? What does it determine?
exergonic: a reaction where energy is released. Because the reactants lose energy (G
decreases), Gibbs free energy (ΔG) is negative under constant temperature and
pressure
endergonic:a chemical reaction in which the standard change in free energy is positive,
and energy is absorbed - Correct Answers -What does it mean when a reaction is
exergonic or endergonic?
An exergonic reaction (favorable) coupled to an endergonic reaction (unfavorable) is an
energetically favorable reaction. - Correct Answers -What happens if an endergonic and
exergonic reaction are coupled?
lowers the activation energy of a reaction - Correct Answers -What does an enzyme do?
B. matrix. - Correct Answers -Specify the localization of the enzyme isocitrate
dehydrogenase within mitochondria?
A. ribosome.
B. matrix.
C. inner membrane.
D. outer membrane.
E. intermembrane space.
acetyl CoA --> citrate --> isocitrate --> alpha-ketoglutarate --> succinylCoA --> succinate
--> fumarate --> malate --> oxaloacetate
pneumonic: always come in and suck some fruity melons only - Correct Answers -What
is the order of the TCA cycle?
isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, succinate
dehydrogenase, malate dehydrogenase
pneumonic: I always suck melons - Correct Answers -What 4 enzymes are involved in
the TCA cycle?
The organofluorine compound sodium fluoroacetate is a potent metabolic poison that
targets the citric acid cycle. The fluoroacetate metabolite fluoroacetyl-CoA reacts with
oxaloacetate (a reaction catalyzed by citrate synthase) to form the metabolic inhibitor
fluorocitrate. Fluorocitrate binds and inactivates aconitase, thereby halting the citric acid
, cycle with induction of cellular energy crisis - Correct Answers -What does sodium
fluoroacetate do to the TCA cycle?
B. transfer electrons from the acetyl portion of acetylCoA to NAD+ and FAD. - Correct
Answers -The principal function of the TCA cycle is to:
A. generate CO2.
B. transfer electrons from the acetyl portion of acetylCoA to NAD+ and FAD.
C. oxidize the acetyl portion of acetylCoA to oxaloacetate.
D. generate heat from the oxidation of acetylCoA
E. dispose of excess pyruvate and fatty acids.
The cancer cell uses intermediates in the glycolytic pathway and the TCA cycle to
produce nucleotides, fatty acids and amino acids to serve as building blocks for
macromolecules. Many cancer cells also take up more glutamine than normal cells, to
replenish TCA cycle intermediates and to provide nitrogen for the synthesis of
nucleotides. - Correct Answers -How do cancer cells target the TCA cycle?
Nucleolus - Correct Answers -What is this?
TCA cycle enzymes, fatty acid oxidation enzymes, mtDNA, mtRNA, mitochondrial
ribosomes - Correct Answers -What is inside the mitochondria matrix?
impermeable to most small ions, small and large molecules - Correct Answers -What is
the inner membrane of the mitochondria permeable/impermeable to?
mitochondrial DNA: is found in cell mitochondria and contains genetic material from only
the mother
nuclear DNA: found in the cell nucleus and contains genetic material from both parents -
Correct Answers -What is the difference between mitochondrial DNA and nuclear DNA?
OXPHOS diseases originate from mtDNA mutations characterized by maternal
inheritance. - Correct Answers -Where do oxphos diseases originate from?
aging neurodegeneration cancer
mitochondrial disease - Correct Answers -What does constitutive electron leakage
during mitochondrial electron transport cause?
Reactive oxygen species (ROS) are derivatives of oxygen that are more reactive than
molecular oxygen
they come from the incomplete reduction of oxygen to water - Correct Answers -What
are reactive oxygen species? Where do they come from?
Superoxide (O2-)
Hydrogen Peroxide (H2O2)
QUESTIONS AND ANSWERS
I: Molecular motors driven by ATP hydrolysis
II: Performing anabolic biochemical work example: glycogen biosynthesis
III: ATP-dependent transmembrane transport: the gastric proton pump as drug target
IV: Transmembrane transport: a plasma membrane ATPase as drug target
V: ATP-dependent transmembrane transport: Sodium:serotonin symporter - Correct
Answers -What are the 5 uses for ATP?
A proton pump inhibitor (PPI) acting by irreversibly blocking the H+/K+ ATPase (proton
pump) of the gastric parietal cell.
ex.) omeprazole - Correct Answers -How does a proton pump inhibitor (PPI) work?
Digoxin (digitalis) works by inhibiting heart muscle cell sodium- potassium ATPase. This
results in an increased intracellular concentration of sodium, which in turn increases
intracellular calcium by passively decreasing the action of the sodium-calcium
exchanger (antiporter) in the sarcolemma. The increased intracellular calcium gives a
positive inotropic effect (increased heart contractility). - Correct Answers -How does
digoxin work?
SERT is the target of many antidepressant medications, including those of the selective
serotonin reuptake inhibitor (SSRI) class: example fluoxetine (ProzacTM)
The serotonin transporter (SERT) is an integral membrane protein that transports the
neurotransmitter serotonin from synaptic spaces into presynaptic neurons. It is a
member of the sodium:neurotransmitter symporter family. - Correct Answers -What is
the target of many antidepressant medications?
change in free energy
-energy available to do work,
-approaches zero as a reaction proceeds to equilibrium,
-predicts whether a reaction is favorable - Correct Answers -What is the ∆G in gibbs
free energy?
change in enthalpy
-heat released or absorbed during a reaction
-does not predict whether a reaction is favorable - Correct Answers -What is the ∆H in
gibbs free energy?
,change in entropy
-measure of randomness
-does not predict whether a reaction is favorable - Correct Answers -What is the ∆S in
gibbs free energy?
The Gibbs Free Energy provides a way to determine if a reaction is favorable or
favorable in the direction written under a given pressure and temperature. - Correct
Answers -What is the equation for gibbs free energy? What does it determine?
exergonic: a reaction where energy is released. Because the reactants lose energy (G
decreases), Gibbs free energy (ΔG) is negative under constant temperature and
pressure
endergonic:a chemical reaction in which the standard change in free energy is positive,
and energy is absorbed - Correct Answers -What does it mean when a reaction is
exergonic or endergonic?
An exergonic reaction (favorable) coupled to an endergonic reaction (unfavorable) is an
energetically favorable reaction. - Correct Answers -What happens if an endergonic and
exergonic reaction are coupled?
lowers the activation energy of a reaction - Correct Answers -What does an enzyme do?
B. matrix. - Correct Answers -Specify the localization of the enzyme isocitrate
dehydrogenase within mitochondria?
A. ribosome.
B. matrix.
C. inner membrane.
D. outer membrane.
E. intermembrane space.
acetyl CoA --> citrate --> isocitrate --> alpha-ketoglutarate --> succinylCoA --> succinate
--> fumarate --> malate --> oxaloacetate
pneumonic: always come in and suck some fruity melons only - Correct Answers -What
is the order of the TCA cycle?
isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, succinate
dehydrogenase, malate dehydrogenase
pneumonic: I always suck melons - Correct Answers -What 4 enzymes are involved in
the TCA cycle?
The organofluorine compound sodium fluoroacetate is a potent metabolic poison that
targets the citric acid cycle. The fluoroacetate metabolite fluoroacetyl-CoA reacts with
oxaloacetate (a reaction catalyzed by citrate synthase) to form the metabolic inhibitor
fluorocitrate. Fluorocitrate binds and inactivates aconitase, thereby halting the citric acid
, cycle with induction of cellular energy crisis - Correct Answers -What does sodium
fluoroacetate do to the TCA cycle?
B. transfer electrons from the acetyl portion of acetylCoA to NAD+ and FAD. - Correct
Answers -The principal function of the TCA cycle is to:
A. generate CO2.
B. transfer electrons from the acetyl portion of acetylCoA to NAD+ and FAD.
C. oxidize the acetyl portion of acetylCoA to oxaloacetate.
D. generate heat from the oxidation of acetylCoA
E. dispose of excess pyruvate and fatty acids.
The cancer cell uses intermediates in the glycolytic pathway and the TCA cycle to
produce nucleotides, fatty acids and amino acids to serve as building blocks for
macromolecules. Many cancer cells also take up more glutamine than normal cells, to
replenish TCA cycle intermediates and to provide nitrogen for the synthesis of
nucleotides. - Correct Answers -How do cancer cells target the TCA cycle?
Nucleolus - Correct Answers -What is this?
TCA cycle enzymes, fatty acid oxidation enzymes, mtDNA, mtRNA, mitochondrial
ribosomes - Correct Answers -What is inside the mitochondria matrix?
impermeable to most small ions, small and large molecules - Correct Answers -What is
the inner membrane of the mitochondria permeable/impermeable to?
mitochondrial DNA: is found in cell mitochondria and contains genetic material from only
the mother
nuclear DNA: found in the cell nucleus and contains genetic material from both parents -
Correct Answers -What is the difference between mitochondrial DNA and nuclear DNA?
OXPHOS diseases originate from mtDNA mutations characterized by maternal
inheritance. - Correct Answers -Where do oxphos diseases originate from?
aging neurodegeneration cancer
mitochondrial disease - Correct Answers -What does constitutive electron leakage
during mitochondrial electron transport cause?
Reactive oxygen species (ROS) are derivatives of oxygen that are more reactive than
molecular oxygen
they come from the incomplete reduction of oxygen to water - Correct Answers -What
are reactive oxygen species? Where do they come from?
Superoxide (O2-)
Hydrogen Peroxide (H2O2)
