BIOCHEM PLEASE ONLY ANSWER IF YOU TRULY UNDERSTAND IT!! I posted this many times

Question

BIOCHEM

PLEASE ONLY ANSWER IF YOU TRULY UNDERSTAND IT!! I posted this many times, and people have been giving wrong answers. Also ONLY answer if you can answer it FULLY.

1. Please refer to Table 15-1 to answer the following questions (below).

a. Arrange the following molecules of the electron transport chain in increasing electron affinity. FAD, CoQ (ubiquinone), O2, Cytochrome C, and NAD+.

b. Calculate the (Delta) G°' for the oxidation of succinate by NAD+ and by FAD. Based on your calculated values, suggest why FAD rather than NAD+ is the electron acceptor of the succinate dehydrogenase reaction as observed in TCA and electron transport chain. Please show complete work for full credit.

Explanation / Answer

a) more the electron affinity more the electrode potential value

The values are

FAD= 0

CoQ = 0.045

O2 = 0.815 V

Cytochrome c = 0.235

NAD+ = -0.315

So the order will be:

O2 > Cytochrome C > CoQ > FAD > NAD+.

b) Calculate the (Delta) G°' for the oxidation of succinate by NAD+ and by FAD

DeltaG0 = -nF (E0reduction - E0oxidation)

(i) for succinate and NAD+

E0succinate = E0oxidation = -0.03V

E0NAD+ = E0reduction = -0.315

DeltaG0 = -nF (E0reduction - E0oxidation) = -2 X 96485 X (-0.315 + 0.03) = 54996.45 Joules /mole = 54.996 KJ / mole

(ii) for succinate and FAD

E0succinate = E0oxidation = -0.03V

E0NAD+ = E0reduction = 0

DeltaG0 = -nF (E0reduction - E0oxidation) = -2 X 96485 X (0 + 0.03) = -5789.1 J / mole = -5.789 KJ / mole

So the DeltaG0 value for FAD and succinate is negative hence the reaction will be spontaneous hence it is better oxidizing agent then NAD+

Thus FAD rather than NAD+ is the electron acceptor of the succinate dehydrogenase reaction as observed in TCA and electron transport chain

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