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ATP synthesis in mitochondrion is driven by energy produced in electron
transport pathway. And this energy is stored in the form of ________. ATP synthesized in this process is called _____ hosphorylation.
ATP produced in TCA cycle is called ______ phosphorylation.
- proton gradient
- substrate level
Which of the following step does NOT produce NADH?
Succinate ----> fumarate
All the enzymes in the TCA cycle are water soluble and located in the matrix
of mitochondrion. True or False.
Pyruvate dehydrogenase is regulated by which covalent modification?
The precise mechanism of NADH-UQ reductase is unknown, but the electron
Which complex is not coupled with proton translocation in electron
transport pathway _______.
The components of electron transport chain include two mobile electron
carriers, a lipid-soluble molecule _________ and a water-soluble protein __________.
Which of the following enzyme is not allosterically inhibited by high level of
Please write down the coenzymes involved in the reaction: pyruvate -------> acetyl-CoA.
FAD, CoA, Liopic Acid, TPP,NAD+/NADH
The terminal electron acceptor in eukaryotic aerobes is _______.
If the F0 unit of ATP synthase has the stoichiometry of a1b2c12, How many
degrees of rotation of one of the c subunits relative to the a subunit occur
with each proton transferred to the matrix?
Which enzyme in the citric acid cycle proceeds by a similar mechanism and
with similar cofactors as pyruvate dehydrogenase?
Q cycle is a unique redox pathway in ______.
Which complex of the electron transport chain does not contain a
NADH-Coenzyme Q reductase
The electron transfer in complex IV is from cytochrome c to _____ to
heme a, then to ________ and in the end to O2.
The energy-requiring step of ATP synthesis in ATP synthase is the release of ATP. True or False.
Electron transport causes the proton translocation of protons across the
inner membrane of mitochondria. What compartment has a lower pH?
The glycerophsophate shuttle and ________ shuttle feed the electrons from _______ into electron transport in mitochondrion.
- NADH produced from glycolysis in cytosol
In your own words, please describe the purpose of TCA cycle in two or three
sentences. Please be brief and you don’t have to go into details of the
To oxidize Acetyl-CoA into CO2 and release the energy in the form of NADH
Please draw the pathway how the electrons from NADH are transferred to
O2. Write down the full names of the complexes.
NADH----> NADH-UQ reductase----> UQ----> UQ-cytochrome c reductase-----> cytochrome c ----> cytochrome c oxidase-----> O2
Please write down the reaction(s) that produces GTP in TCA cycle. Include
the enzymes (coenzymes) and the structures of the substrates and products.
And write down an intermediate (structure/name) during catalysis.
For each acetate oxidized, the net outcome of the TCA cycle is...
two molecules of CO2, one ATP, 3 NADH and one FADH2
Which enzyme in the citric acid cycle catalyzes the reaction that directly produces a high-energy nucleoside triphosphate?
Place these substrates in the correct sequence for the TCA cycle.
a, b, c, d
Pyruvate carboxylase catalyzes the most important anaplerotic reaction which is.....
ATP and biotin-dependent carboxylation of pyruvate to oxaloacetate
Both fumarase and aconitase catalyze the addition of the elements of water across a double bond. This addition is:
In the isomerization of citrate to isocitrate, the intermediate is:
Which reaction of the TCA cycle catalyzes a substrate-level phosphorylation?
Place these enzymes in the correct sequence for the TCA cycle:
a, c, b, d
The three main regulatory sites in the TCA cycle are:
citrate synthase, isocitrate dehydrogenase, α-ketoglutarate dehydrogenase
Which of the following is not true concerning citrate synthase?
the reaction requires an input of energy from ATP
Which enzyme of the TCA cycle is an integral membrane protein?
Pyruvate dehydrogenase (PDH) is regulated by covalent modification. The PDH kinase phosphorylates and inactivates PDH. The PDH kinase is allosterically activated by a low:
Which of the following enzymes catalyzes an anaplerotic reaction for the TCA cycle?
- pyruvate carboxylase
- PEP carboxylase
- malic enzyme
- (All of the Above)
The oxidative decarboxylation of pyruvate to acetyl-CoA is catalyzed by:
pyruvate dehydrogenase complex
Which enzyme in the citric acid cycle proceeds by a similar mechanism and with similar cofactors as pyruvate dehydrogenase?
The succinate dehydrogenase reaction is stereospecific. The mechanism involves the removal of:
the pro-S hydrogen of one carbon and the pro-R hydrogen of the other carbon
The essential feature of thiamine pyrophosphate chemistry is:
a cationic imine N that acts as an electron sink
The chemiosmotic coupling hypothesis proposed by Peter Mitchell states that:
electron transport drives protons across the inner mitochondrial membrane from the matrix to the intermembrane space.
The flow of electrons through complex IV is:
cyto c to CuA to cyto a to cyto a3-CuB to O2
Which of the following electron carriers is the most mobile?
Which of the following is not an inhibitor of complex I, II, or III?
Which of the following electron carriers participates in both one and two electron transfers?
The malate –aspartate shuttle transfers 2e- from:
- -mitochondrial NADH to cytosolic NADH
- -cytosolic NADH to mitochondrial NADH
- -cytosolic malate to mitochondrial malate
- (All of the Above)
Which of the following cytochromes of the electron transport chain is NOT tightly bound to an integral membrane protein?
Oligomycin is a macrocyclic antibiotic that inhibits oxidative phosphorylation. It....
inhibits proton flow by binding to the Fo unit of ATP synthase
Proton transfer through the Fo subunit of ATP synthase causes a:
T to O conformational change of a β-subunit with release of ATP
Where are most of the processes of electron transport and oxidative phosphorylation localized in eukaryotes?
inner mitochondrial membrane
In EACH of the two steps of the Q-cycle, when fully reduced coenzyme Q, QH2, is re-oxidized by complex III:
a. one e- is transferred to cytochrome c1
b. one e- is transferred to the bL heme
c. two H+ are released on the cytosolic side of the membrane
d. one H+ is taken up on the matrix side of the membrane
e. one e- is transferred from the Qp site on the matrix side to the Qn site on the cytosolic side of the membrane
a, b, c
If the Fo unit of ATP synthase has the stoichiometry of a1b2c9, how many degrees of rotation of one of the c subunits relative to the α subunit occur with each proton transferred to the matrix?
Which of the following is true about the flavoprotein complexes?
a. they are all sites where protons are transferred across the inner mitochondrial membrane
b. they all contain FMN
c. they all contain FAD
d. they all contain Fe-S centers
e. they all transfer electrons to UQ
d and e only
Which of the following are true?
a. the glycerophosphate shuttle and the malate-aspartate shuttle yield the same number of ATP's starting from NADH in the cytosol
b. the glycerophosphate shuttle yields the same number of ATP's per 2 electrons donated as complex II of the electron transport chain
c. the malate-aspartate shuttle is more energy efficient than the glycerophosphate shuttle
d. the glycerophosphate shuttle can donate electrons to the electron transport chain even when the cytosolic [NADH] is low
e. the malate-aspartate shuttle is essentially irreversible
b, c, and d
The terminal electron acceptor in eukaryotic aerobes is:
Which complex of the electron transport chain does not contain a cytochrome?
NADH-coenzyme Q reductase
Dinitrophenol, a hydrophobic weak acid with a pKa of 9, is an uncoupler of oxidative phosphorylation. It:
collapses the proton gradient
Which of the following is a mobile, lipid-soluble electron carrier found in the inner mitochondrial membrane?