Il-11. Is it possible for the same substance (molecule) to be either an electron
ID: 214767 • Letter: I
Question
Il-11. Is it possible for the same substance (molecule) to be either an electron donor or an electron acceptor for the same organism, under different conditions? Explain, using the redox tower, and include complete coupled half reactions in your answer. Redox Couple E, (v) COucose (-0 43)24e50 -o.40 (-0.38) 6e INAD 0.20 SPMS (-0 28) 20 FAD FADH (-022) pyruvatelactate (-0.19) 2e M e~ 12e!/// s.o so2 (0.024)2 fumarato/succinate(.0 03) 2 cylochromeb0 035) te Ubiquinone+0.11) 20 FeFo (0 2) 1e (pH 7) 0.00 .0 10 0.20 *0.30 0.40 060 NO NO-0 42)2e NO,IIN, (0.74) 5e FeFe (10761 (pH 2) -+0 70 O/H.O (+0.82) 2e Il-12. Is NADH a better electron donor than H2? Is NAD+ a better e- acceptor than 2 H+? Explain how you determined your answers, referring to the redox tower below.Explanation / Answer
yes same substance can be electron donor and acceptor under different situations.If we observe redox tower then nicotinamide Adenine diphosphate is a compund which under different conditions acts as a electron donor and acceptor.Its form NAD+ is electron acceptor and NADH is electron donor.half reactions can stated as
NAD/NADH + 2e-
Similarly Flavin adenine dinucleotide is both electron acceptor(FAD+) and electron donor(FADH)
FAD/FADH + 2e-
2. No If we see the redox tower then molecule which above is more electron donor than the molecule below.So H2 is better electron donor than NADH.
Yes NAD is better electron acceptor than 2H+ because the molecule which is below is more electron acceptor than the molecule above.SInce NAD is below than 2H+ then it is better electron acceptor