Exam 14: Electron Transport, Oxidative Phosphorylation, and Oxygen Metabolism

Proton-driven rotation of the c-ring of the F0 unit of the F1F0 ATP synthase is required for complete passage of protons from the intermembrane space to the matrix.

Which of the following is NOT an electron acceptor in the mitochondrial respiratory chain?

Energy derived from oxidation of acetyl-CoA in the citric acid cycle is used for the production of ________ in brown adipose tissue because the mitochondria are rich in UCP1.

Which of the following is NOT true of respiratory control?

In animal cells the mitochondrial electron transport chain is responsible for reoxidizing most of the NADH produced by oxidative pathways regardless of the cellular compartment in which it was produced.

Which of the following statements about oxidative phosphorylation by ATP synthase is FALSE?

Electrons are transferred through the respiratory chain from reduced NADH or FADH2 to oxygen in small steps with each step in the pathway associated with a slightly more ________ reduction potential.

Electron transport through NADH-Coenzyme Q reductase (Complex I) is accompanied by transfer of ________ protons from the matrix to the intermembrane space.

The Q cycle is responsible for transferring electrons from a two-electron donor ________ to a one-electron acceptor ________ at the point of complex III of the mitochondrial respiratory chain.

Calculate the free energy change associated with transporting one proton from the matrix to the intermembrane space at 37∘C where the electrical potential across the membrane is ~ = 170 mV and the △pH is +0.75.

Calculate the efficiency of energy conversion from glucose under aerobic conditions assuming that 32 moles of ATP are produced for each mole of glucose and given that △G0' for glucose oxidation is -2870kJ/mol and the △G0' for ATP hydrolysis is -32.2 kJ/mol.

All of the cytochromes in the mitochondrial respiratory chain contain the same heme moiety as found in hemoglobin.

Which of the following statements is FALSE?

________, which are potentially damaging, are generated because the interactions between one electron and two electron carriers are not 100% efficient.

Oligomycin is an inhibitor of ADP phosphorylation because it blocks the flow of protons through the ________.

Which of the following is NOT involved in the enzymatic inactivation of reactive oxygen species?

Calculate the standard free energy change for the reactionFADH2 + 1/2O2 → FAD + H2O given that the standard reduction potential for the reduction of oxygen to water is +0.82 V and for the reduction of FAD to FADH2 is +0.03 V.

CoQ carries electrons from NADH-Coenzyme Q reductase and succinate dehydrogenase as well as other flavoproteins to CoQ:Cytochrome c oxidoreductase.

The ATP yield from NADH transported across the mitochondrial inner membrane by the glycerol phosphate shuttle is the same as if the malate/aspartate shuttle were used.