P2.5 5.Consider the oxidation of a mole of NADH using the following half reactions:12 O2 + 2 e + 2 H+ → H₂ONAD + 2 e + H+ → NADHE = 0.83 VE" = -0.32 Va) Determine E" and AG" for the oxidation of a mole of NADH by oxygen. Show all work forthe calculation of both values and write out the overall reaction.b) Assume that this occurred in a mitochondria with a defective complex IV that resulted inno proton pumping at complex IV (all other complexes pumped protons in their normalfashion). How many moles of protons are pumped as a result of the oxidation of a mole ofNADH using this slightly defective electron transport chain?c) If all of the protons calculated above could be used for ATP production by themitochondrial ATP synthase, how many moles of ATP could be produced?d) If the AG for ATP synthesis is about 50 kJ/mol, what percentage of the energy fromNADH oxidation is captured in ATP formation?

∆G'0 = -nF∆E'0 here; ∆G'0 is the change in standard Gibbs free energy. 'n' is the number of electrons transferred in the redox reaction. In our case, during NADH oxidation, 2 electrons are transferred from NADH to 12 O2 . So, n=2 . 'F' is the Faradays constant. It has a value of 96,485 J V-1 mol-1 . ∆E'0 =E'0(of electron acceptor) - E'0(of electron donor) The electron acceptor here is 12 O2 and electron donor is NADH. E'0 is the standard reduction potential value. So, simply use the standard reduction potential values for reduction half reactions involving 12 O2 and NADH. The E'0 values for half reactions involving 12 O2 and NADH are given in question, so we just need to use these values on the above equation. Do not reverse the sign! ∆E'0 = 0.83V - (-0.32V) =1.15 V So, E'0 of oxidation of a mole of NADH by O2 (i.e. ∆E'0 ) is 1.15 V . ∆G'0 = -2×96485 J V-1 mol-1 × 1.15 V =-221915.5 J mol-1 Electron Transport Chain (ETC) consists of four protein complexes called Complex I, II, III and IV that transport electron from electron donors (NADH/FADH2) to electron acceptor: Oxygen. Oxidation of NADH in ETC involves the transfer of 2 electrons from NADH to ETC. These 2 electrons finally reach O2 and reduces it. For each pair of electrons transferred through ETC; Complex I and III pumps 4 protons each from mitochondrial matrix to Intermembrane space (IMS). Complex II do not pump any protons. Complex IV pumps 2 protons from mitochondrial matrix to Intermembrane space (IMS). Since, complex IV do not pump protons here. The total number of protons pumped as a result of oxidation of 1 mole of NADH by the slightly defective ETC = 4 + 4 = 8 protonsFor an ATP synthase with 12 c-subunits ( an ATP synthase have an average of 12 c-subunits), 4 protons have to travel back from IMS to mitochondrial matrix via the ATP synthase to produce and release 1 mole of ATP. Our slightly defective ETC pumped 8 protons to IMS. If all these 8 protons are to travel back from IMS to mitochondrial matrix via the ATP synthase, then it would produce 2 moles of ATP .Oxidation of 1 mole of NADH yielded 221,915.5 J energy. Synthesis of 1 mole of ATP require 50 KJ = 50,000 J. We produced 2 moles of ATP as a result of the oxidation of 1 mole of NADH. So, 2 moles of ATP synthesis requires 50,000 + 50,000 = 100,000 J energy. % energy captured =100,000 J221,915.5 J ×100 =45.06 % i.e. 45.06% of energy from NADH oxidation is captured in ATP formation.