Which of the following components of mitochondrial electron transport can act as 1-electron or 2-electron carriers?
A) coenzyme Q and flavins
B) cytochrome c, coenzyme Q, and flavins
C) NADH, non-heme iron, cytochrome c, coenzyme Q, and flavins
D) non-heme iron, cytochrome c, coenzyme Q, and flavins

Question

Quizplus · Accepted Answer

Coenzyme Q (ubiquinone) and flavins (such as FAD and FMN) can both act as either 1-electron or 2-electron carriers in the mitochondrial electron transport chain. Only coenzyme Q and the flavins are capable of both 1- and 2-electron transfer reactions. Ubiquinone can undergo either 1- or 2-electron reactions leading to formation of the reduced quinol, the oxidized quinone, and the semiquinone intermediate. NADH and FADH₂ can only carry out obligatory 2-electron reactions and the cytochromes can only carry out 1-electron reactions.

Which of the Following Components of Mitochondrial Electron Transport Can