Q. 18.48 - An Introduction to General, Organic, and Biological Chemistry

Question

How is ${\mathrm{FADH}}_2$ oxidized in electron transport?

Step-by-Step Solution

Answer

The ${\mathrm{FADH}}_2$ get oxidized in electron transport by  interacting with $\mathrm{CoQ}$ in Complex $\mathrm{II}$

Step 1: Given information

We need to find the way by which ${\mathrm{FADH}}_2$ get oxidized while electron transfer

Step 2: Explanation

When $FAD{H}_2$ interacts with $\mathrm{CoQ}$ in Complex $\mathrm{II}$, it is immediately oxidized. $\mathrm{CoQ}$ absorbs electrons and hydrogen ions directly from ${\mathrm{FADH}}_2$, which was formed in the citric acid cycle after the production of fumarate from succinate via oxidation by succinate dehydrogenase. After absorbing electrons and hydrogen ions from ${\mathrm{FADH}}_2$, $\mathrm{CoQ}$ is reduced to ${\mathrm{CoQH}}_2$, while ${\mathrm{FADH}}_2$ is oxidized to $\mathrm{FAD}$ after releasing electrons and hydrogen ions. Later oxidative pathways, $\mathrm{FAD}$ will be employed in other oxidative reactions.