Explain how you get the answer for these 3 Biology questions please? (Answers at

Question

Explain how you get the answer for these 3 Biology questions please? (Answers attached)

2) The overall equation for electron transport is: NADH + H+ + 1/2 O2 ? NAD+ + H2O (Delta E=+1.14, Delta G=-52668)

a) Some of the energy which is released by this process is used to synthesize 3 moles of ATP. What is the efficiency of energy capture in this process?

(Answer: 43%)

3)3) The following are the reduction potentials for 4 newly discovered compounds:

A(ox) + 2e- ? A(red) Eo = -1.00 volts

B(ox) + 2e- ? B(red) Eo = -0.95 volts

C(ox) + 2e- ?????? C(red) Eo = -0.85 volts

D(ox) + 2e- ?????? D(red) Eo = -0.75 volts

Which, if any, of the following reactions, proceeding as written, will yield sufficient energy to synthesize 1 ATP? Reaction 1: A(red) + B(ox) ?A(ox) + B(red)

Reaction 2: A(red) + C(ox) ? A(ox) + C(red)

Reaction 3: A(red) + D(ox) ? A(ox) + D(red)

(Answer: Only Reaction #3)

4) The oxidation/reduction reaction: X(ox) + Y(red) ? X(red) + Y(ox) involves a transfer of 2 electrons and has a ?Go = -23,000 cal/mole, as written. Determine the ?Eo for this reaction.

(Answer: Delta E=+0.5)

I want to learn how to do them. Thank you.

Explanation / Answer

ok i got the last solution first. let me explain that.

question 4) formula to calculate E is as follows: where n is number of electrons. F is faraday's constant= 96.5 kJ/mole. now in question Go= -23000cal/mol has to be ocnverted into kJ/mole thus it isGo=-96.232 kJ/mole.

Go=-nFEo

thus, -96.232= -2 X 96.5 X Eo

Eo= 0.498 which is = +0.5 :)

1)G =-220.36kJ/mol. (-52668) E=+1.14

actually im able to calculate efficiecy as 38% not 43%. see below.

if synthesis of ATP occurs via 1mol NADH reoxidation during chemiosmosis. it will require the transfer of 10mol protons from matrix to intermembrane space. which requires 200kJ or 20kJ/mole of proton transfer.

thus, 10protons require a supply of 200kJ energyto make one ATP we need 4 mol of protos. from intermembrane space to to matrix via the ATP synthase.

thus, their transfer would yield= 4X20kJ=80 kJ.

we know that , synthesis of ATP requires 30.5kJ.

coupling ATP synthesis with NADH reoxidation will give 30.5/80X100= 38% efficiency.

rest is released as heat of coupling ATP synthesis with NADH reoxidation.

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