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Example Questions
Example Question #41 : Electron Transport And Oxidative Phosphorylation
Reactive oxygen species are by-products of the electron transport chain. Which of the following are considered reactive oxygen species?
All of these
None of these
Hydroxyl radical
Hydrogen peroxide
Superoxide
All of these
Reactive oxygen species are superoxide, hydrogen peroxide, and hydrogen radicals. They are degraded by catalase, superoxide dismutase, and glutathione peroxidase. Neutrophils use reactive oxygen species to kill bacteria during the phagocytic oxidative burst.
Example Question #42 : Electron Transport And Oxidative Phosphorylation
Which of the following are uncouplers of the electron transport chain?
I. Carbon monoxide
II. 2,4-Dinitrophenol
III. Nitric oxide
IV. Aspirin
I, III, and IV
I and II
I and III
I and IV
II and IV
II and IV
Uncouplers of the electron transport chain decrease the proton gradient and thus decrease ATP synthesis. Most energy from the electron transport chain is released as heat. The most common uncouplers are 2,4-dinitrophenol and aspirin, as well as thermogenin. Carbon monoxide is an inhibitor of the electron transport chain, not an uncoupler. Nitric oxide does not affect directly the electron transport chain.
Example Question #41 : Electron Transport And Oxidative Phosphorylation
What is an electron acceptor in oxidative phosporylation?
Oxygen
ATP
Carbon dioxide
Carbon monoxide
NADH
Oxygen
Oxygen is an electron acceptor. In the absence of oxygen (hypoxia) cells cannot generate ATP in the mitochondria. Instead, they will utilize glycolysis. Oxygen is required to carry out the electron transport chain and produce ATP via oxidative phosphorylation.