Question

In electron transport, which respiratory complex is not involved in the flow of electrons from FADH2?

A) complex I
B) complex II
C) complex III
D) complex IV
E) all of the above

Answer 1

Complex I is not involved in the electron flow initiated by FADH2 in the electron transport chain. FADH2 donates electrons directly to Complex II, bypassing Complex I.

Step-by-step explanation:

In the electron transport chain (ETC) of cellular respiration, FADH₂ donates electrons directly to Complex II, also known as succinate dehydrogenase. This bypasses Complex I, which instead receives electrons from NADH. The electrons from FADH₂ then flow through Complex III and Complex IV before reaching oxygen, the final electron acceptor. Thus, Complex I is not involved in the electron flow initiated by FADH₂.