Oxidative Phosphorylation (LM 15)

The malate shuttle is thought to be of more universal utility than the glycerol 3-phosphate shuttle, because:

• NADH can be transferred intact from the cytoplasm to the mitochondrial matrix using this shuttle.

• Mitochondrial FADH2 is produced using the malate shuttle.

• Malate uncouples oxidation from phosphorylation inside mitochondria.

• Three rather than 2 ATP can be generated per atom of O2 consumed from mitochondrial NADH generated in the malate shuttle.

• FADH2 cannot be oxidized in the electron transport chain.

Which one of the following functions as a lipid-soluble mobile electron carrier in the electron transport chain?

• Cytochrome b

• Copper

• Flavin mononucleotide

• Coenzyme Q

• Iron-sulfur protein

Cytochrome c reductase is synonymous with which complex in the electron transport chain?

• I

• II

• III

• IV

• V

Which one of the following is known to block movement of H+ through the mitochondrial F0 channel, thereby inhibiting ATP formation?

• Carbon monoxide

• Oligomycin

• Carboxin

• Barbiturates

• Rotenone

Uncouplers of mitochondrial oxidative phosphorylation are associated with all of the following, EXCEPT:

• Hibernation.

• A decrease in mitochondrial pH.

• An increase in fatty acid oxidation in brown adipose tissue.

• Thermogenin.

• An increase in ATP generation.

In the malate shuttle, reducing equivalents from NADH are accepted by which compound in the cytoplasm?

• Pyruvate

• Malate

• Dihydroxyacetone phosphate

• Oxaloacetate

• Aspartate

Which one of the following compounds associated with the ETC is a heme-containing protein?

• Cytochrome c

• Ubiquinone

• NADH

• Coenzyme Q

• Flavin mononucleotide

Which complex serves to bind enzymes containing bound FADH2 to the rest of the ETC?

• NADH-CoQ reductase

• Succinyl-CoQ reductase

• Cyt c reductase

• Cyt c oxidase