Question

The following reaction is part of the electron transport chain. Complete the reaction and identify which species is reduced. The abbreviation Q represents coenzyme Q. Use the appropriate abbreviation for the product.
FADH2+Q→
The reactant that is reduced is: _____

Answer 1

Answer:

$FADH_2+Q --> FAD + QH_2$

The reactant that is reduced is Q.

Explanation:

The complete equation for the reaction is such that:

$FADH_2+Q --> FAD + QH_2$

Two molecules of H atom is lost from $FADH_2$ and the H atoms are gained by the coenzyme Q. Consequently,  $FADH_2$ becomes FAD while Q becomes $QH_2$.

From the definition of oxidation as loss of hydrogen and reduction as the addition of hydrogen, it can be concluded that the FADH2 that lost hydrogen is a reactant that is oxidized while the coenzyme Q that gained hydrogen is a reactant that is reduced in the reaction.