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

`FADH_2+Q --> FAD + QH_2`

The reactant that is reduced is Q.

Step-by-step 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.