Question

Which of the following aerobic electron transport chain components lacks an a- and/or c-type heme as a cofactor? Choose one or more: A. complex I B. complex II C. complex III D. cytochrome c E. complex IV

Answer 1

A. complex I

B. complex II

Step-by-step explanation:

Complex I of the electron transport chain is NADH dehydrogenase. It has FMN and Fe-S prosthetic groups. Complex II of ETC is the succinate dehydrogenase. It also has FAD and Fe-S as prosthetic groups. Both complexes I and II lack any type of heme as a prosthetic group. Complex III (cytochrome c oxidoreductase), cytochrome c and complex IV have heme cofactors. Heme A is present in a-type cytochromes while heme C is present in c-type cytochromes.