Question

Calculate the standard free energy change for each of the following steps. Which steps have enough free energy to synthesize ATP? I. NADH passing its electrons to NADH dehydrogenase. 11. ŅADH dehydrogenase passing its electrons to Q III. Q passing its electrons to cvtochrome b, then cyto b to cyto cl (cytochrome oxidoreductase IV. Cyto cl passing its electrons to cyto c V. Cyto c passing its electrons to cyto a, then cyto a to cyto a3 VI. Cyto a3 passing its electrons to oxygen

Answer 1

When NADH passes through electron transport system it provide 3 ATP ..in three region it provide enough free energy to synthesize ATP ... IN complex -I , II, III .

I) when electron passes from NADH to Co Q . (Complex - I)

II) cyto b to cyt c1 ( complex -III)

III) Cyt a3 to O2 ( complex - Iv)

You know oxidation is loss of electron . Reduction is gain of electron. ( Tendency to accept electron ) . Hear NADH is oxidise and loose electron. Then electron transfer through electron transport chain.

Oxygen have highest reduction potential ( tendency to accept electron) . So electron through electron transport chain reaches at oxygen.

In electron transport chain continuously reduction potential increases. Co Q have reduction potential is ( 0.045) , Cyt b (0.077) Cyt c1 ( 0.22) Cyt c (0.235) Cyt a ( 0.29 ) Cyt a3 ( 0.385) and O2 Have highest (0.815) ..

The relation between reduction potential and free energy is

∆G= - nf∆E , hear ∆G = FREE ENERGY , ∆E = reduction potential, n = electron transfer, f - Faraday law .

large negative for ∆G require +∆E.

So in complex -i ∆G ( free energy) value is -69.5 kj mol^​-I

in complex-III value is -36.7 ( unit same as upper)

In complex - iv value of free energy is -- 112 .00

So in this three step have enough free energy to produce ATP.

Last accepter of electron is oxygen in ETS. ATP Synthesize from ADP and IP through ATP synthatase in inner mitochondrial membrane. Proton is pump out by three complex in mitochondrial membrane in oxidative phosphorylation.

I describe the process by using formula you can calculate free energy. If any problem just ask me in comment section.