Which of the following is true regarding the given electron transport chain? $\mathrm{CoQ} \rightarrow…
Which of the following is true regarding the given electron transport chain?
$\mathrm{CoQ} \rightarrow \mathrm{Cyt} \mathrm{c} \rightarrow \mathrm{Cyt} \mathrm{aa}_3 \rightarrow \mathrm{O}_2$
$\mathrm{CoQ} \rightarrow \mathrm{Cyt} \mathrm{c}$ is $\mathrm{H}^{+}$absorbing site.
$\mathrm{CoQ} \rightarrow \mathrm{Cyt} \mathrm{c}$ is $\mathrm{H}^{+}$yielding site and $\mathrm{aa}_3 \rightarrow \mathrm{O}_2$ is $\mathrm{H}^{+}$absorbing site.
No $\mathrm{H}^{+}$is absorbed or released.
Solution
In electron transport chain electrons transport through a series of carriers. $\mathrm{H}^{+}$of $\mathrm{NADH}^{+}$ (received from Krebs cycle) is accepted by FAD as a result of which FAD is reduced to $\mathrm{FADH}^{+}$and $\mathrm{NADH}^{+}$is oxidised to $\mathrm{NAD}^{\mathrm{AD}}$. Reduced $\mathrm{FADH}^{+}$is oxidised by $\mathrm{CoQ}$, with the formation of $\mathrm{CoQH}^{+} . \mathrm{H}^{+}$ions then move to Cyt b, then Cyt c, Cyt a and Cyt $\mathrm{aa}_3$. Ultimately these $\mathrm{H}^{+}$are acceped by $\mathrm{O}_2$ and $\mathrm{H}_2 \mathrm{O}$ is formed.