8. Respiration

In the electron transport chain, the final electron acceptor is:

a) H₂O.

b) CO₂.

c) H₂O.

d) O₂.

e) NAD⁺.

Which of the following events takes place in the electron transport chain?

a) The breakdown of glucose into six carbon dioxide molecules.

b) The breakdown of NADH and FADH₂ to carbon dioxide.

c) Harnessing energy from high-energy electrons derived from glycolysis, pyruvate oxidation, and the Krebs cycle.

d) Substrate-level phosphorylation.

The poison cyanide binds to an electron carrier within the electron transport chain and blocks the movement of electrons. When this happens, glycolysis and the citric acid cycle soon grind to a halt as well. Why do you think these other two stages of cellular respiration stop? (Explain your answer.) a. They run out of ATP. b. Unused O2 interferes with cellular respiration. c. They run out of NAD+ and FAD. d. Electrons are no longer available.