.
Acetyl-CoA.
Carbon dioxide (CO2).
Carbon monoxide and then to carbon dioxide.
None of the above.
Water.
Alternate oxidation and reduction of the mitochondrion-bound coenzyme Z can be readily demonstrated.
Removal of coenzyme Z from the mitochondria results in a decreased rate of oxygen consumption.
The rate of oxidation and reduction of mitochondrion-bound coenzyme is of the same order of magnitude as the overall rate of electron transfer in mitochondria as measured by oxygen consumption.
The reduction potential of Z is between that of two compounds known to participate in the electron transport chain
When added to a mitochondrial suspension, coenzyme Z is taken up very rapidly and specifically by the mitochondria.
Coenzyme Q
Cytochrome a3
Cytochrome b
Cytochrome e
Cytochrome f
Cyanide and 2,4-dinitrophenol inhibit the respiratory chain, and oligomycin inhibits the synthesis of ATP.
Cyanide inhibits the respiratory chain, whereas oligomycin and 2,4-dinitrophenol inhibit the synthesis of ATP.
Cyanide, oligomycin, and 2,4-dinitrophenol compete with O2 for cytochrome oxidase (Complex IV).
Oligomycin and cyanide inhibit synthesis of ATP; 2,4-dinitrophenol inhibits the respiratory chain.
Oligomycin inhibits the respiratory chain, whereas cyanide and 2,4-dinitrophenol prevent the synthesis of ATP.
Cytochrome c is a one-electron acceptor, whereas QH2 is a two-electron donor.
Cytochrome c is a two-electron acceptor, whereas QH2 is a one-electron donor.
Cytochrome c is water soluble and operates between the inner and outer mitochondrial membranes
Heart muscle has a high rate of oxidative metabolism, and therefore requires twice as much cytochrome c as QH2 for electron transfer to proceed normally.
Two molecules of cytochrome c must first combine physically before they are catalytically active.
All ATP synthesis will stop.
ATP synthesis will continue, but the P/O ratio will drop to one.
Electron transfer from NADH will cease, but O2 uptake will continue
Electron transfer from succinate to O2 will continue unabated.
Energy diverted from the cytochromes will be used to make ATP, and the P/O ratio will rise.
Be increased in active muscle, decreased in inactive muscle.
Be very low if the ATP synthase is inhibited, but increase when an uncoupler is added.
Decrease if mitochondrial ADP is depleted.
Decrease when cyanide is used to prevent electron transfer through the cytochrome a + a3 complex.
All of the above are true.
Electron transfer in mitochondria is accompanied by an asymmetric release of protons on one side of the inner mitochondrial membrane.
It predicts that oxidative phosphorylation can occur even in the absence of an intact inner mitochondrial membrance.
The effect of uncoupling reagents is a consequence of their ability to carry electrons through membranes.
The membrane ATP synthase has no significant role in the chemiosmotic theory.
All of the above are correct.
Electron transfer in mitochondria is accompanied by an asymmetric release of protons on one side of the inner mitochondrial membrane.
Energy is conserved as a transmembrane pH gradient.
Oxidative phosphorylation cannot occur in membrane-free preparations.
The effect of uncoupling reagents is a consequence of their ability to carry protons through membranes.
The membrane ATPase, which plays an important role in other hypotheses for energy coupling, has no significant role in the chemiosmotic theory.
Oxygen consumption decreases.
Oxygen consumption increases.
The P/O ratio drops from a value of approximately 2.5 to 0.
The proton gradient dissipates.
The rate of transport of electrons from NADH to O2 becomes maximal.
Allows continued mitochondrial ATP formation, but halts O2 consumption.
Halts all mitochondrial metabolism.
Halts mitochondrial ATP formation, but allows continued O2 consumption.
Slows down the citric acid cycle.
Slows the conversion of glucose to pyruvate by glycolysis.
Allow electron transfer in the presence of oligomycin.
Allow oxidative phosphorylation in the presence of oligomycin.
Block electron transfer in the presence of oligomycin.
Diminish O2 consumption in the presence of oligomycin
Do none of the above.
Drug that inhibits the ATP synthase will also inhibit the flow of electrons down the chain of carriers.
For oxidative phosphorylation to occur, it is essential to have a closed membranous structure with an inside and an outside.
The yield of ATP per mole of oxidizable substrate depends on the substrate.
Uncouplers (such as dinitrophenol) have exactly the same effect on electron transfer as inhibitors such as cyanide; both block further electron transfer to oxygen.
Uncouplers “short circuit” the proton gradient, thereby dissipating the proton motive force as heat.
It can synthesize ATP after it is extracted from broken mitochondria.
It catalyzes the formation of ATP even though the reaction has a large positive ΔG'°.
It consists of F0 and F1 subunits, which are transmembrane (integral) polypeptides.
It is actually an ATPase and only catalyzes the hydrolysis of ATP.
When it catalyzes the ATP synthesis reaction, the ΔG'° is actually close to zero.
A very low energy of activation.
Enzyme-induced oxygen exchange.
Stabilization of ADP relative to ATP by enzyme binding.
Stabilization of ATP relative to ADP by enzyme binding.
None of the above.
Create a pore in the inner mitochondrial membrane.
Generate the substrates (ADP and Pi) for the ATP synthase.
Induce a conformational change in the ATP synthase.
Oxidize NADH to NAD+.
Reduce O2 to H2O.
Oxidation of a flavoprotein.
Oxidation of a pyridine nucleotide.
Reduction of a flavoprotein.
Reduction of a pyridine nucleotide.
Reduction of cytochrome a3.
A membrane-bound ATPase couples ATP synthesis to electron transfer.
No CO2 is fixed in the light reactions.
The ultimate electron acceptor is O2.
The ultimate source of electrons for the process is H2O.
There are two distinct photosystems, linked together by an electron transfer chain.
Do not require chlorophyll.
Produce ATP and consume NADH.
Require the action of a single reaction center.
Result in the splitting of H2O, yielding O2.
Serve to produce light so that plants can see underground.
Both contain cytochromes and flavins in their electron carrier chains.
Both processes are associated with membranous elements of the cell.
Both use oxygen as a terminal electron acceptor.
Each represents the major route of ATP synthesis in those cells in which it is found.
Protons are pumped from the inside to the outside of both mitochondria and chloroplast membranes
Glycolysis.
Oxidative phosphorylation.
Pyruvate oxidation.
The citric acid cycle.
All of the above.
Feedback inhibition by CO2.
The availability of NADH from the TCA cycle.
The concentration of citrate (or) the glycerol-3-phosphate shuttle.
The mass-action ratio of the ATD-ADP system.
The presence of thermogenin.
Adult onset diabetes.
Cystic fibrosis.
Hypertrophic cardiomyopathy.
Leber’s hereditary optic neuropathy.
Myoclonic epilepsy.
About 900 mitochondrial proteins are encoded by nuclear genes.
Mitochondrial genes are inherited from both maternal and paternal sources
RRNA and tRNA are imported from the cytoplasm and used in mitochondrial protein synthesis.
The mitochondrial genome codes for all proteins found in mitochondria.
The mitochondrial genome is not subject to mutations.
Escape of cytochrome c into the cytoplasm.
Increased rate of fatty acid β-oxidation.
Increase in permeability of outer membrane.
Uncoupling of oxidative phosphorylation.
Both A and C are correct.
Absorption of CO2 and release of O2.
Absorption of O2 and release of CO2.
Hydrolysis of ATP and reduction of NADP+.
Synthesis of ATP and oxidation of NADPH.
Use of iron-sulfur proteins.
Chlorophyll.
Involvement of cytochromes.
Participation of quinones.
Proton pumping across a membrane to create electrochemical potential.
Use of iron-sulfur proteins.
Absorption spectrum.
Action spectrum.
Difference spectrum.
Reflectance spectrum.
Refraction spectrum.
1-2-3-4-5
3-2-5-4-1
3-5-1-4-2
4-2-3-5-1
5-4-3-2-1
Cyanobacteria and plants have two reaction centers arranged in tandem.
Cyanobacteria contain a single reaction center of the Fe-S type.
Green sulfur bacteria have two reaction centers arranged in tandem.
Plant photosystems have a single reaction center of the pheophytin-quinone type.
Purple bacteria contain a single reaction center of the Fe-S type.
1
2
4
6
8
It can be uncoupled from electron flow by agents that dissipate the proton gradient.
The difference in pH between the luminal and stromal side of the thylakoid membrane is 3 pH units.
The luminal side of the thylakoid membrane has a higher pH than the stromal side.
The number of ATPs formed per oxygen molecule is about three.
The reaction centers, electron carriers, and ATP-forming enzymes are located in the thylakoid membrane.
ATP and O2, but not NADPH.
ATP, but not NADPH or O2 .
NADPH, and ATP, but not O2.
NADPH, but not ATP or O2 .
O2, but not ATP or NADPH.
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