## Chapter 9 #69

Audrey Goodman 1F
Posts: 31
Joined: Fri Sep 29, 2017 7:06 am

### Chapter 9 #69

This problem asks us what amount of moles of ATP could be formed if the Gibbs free energy released in the oxidation of 3 moles NADH were used to generate ATP? Given the three reactions in the problem, I understand why we must multiply the Gibbs free energy of reaction 2 by 3 moles, but we do we also need to multiply that of reaction 3 in order to get the total energy (which we then use to calculate ATP)?

Hannah Chew 2A
Posts: 76
Joined: Fri Sep 29, 2017 7:05 am
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### Re: Chapter 9 #69

We multiply reaction 3 by 3 for the same reason that we multiply reaction 2 by 3. The question asks for 3 mol of NADH, so reaction 2 needs to be multiplied by 3 since the given reaction is for 1 mol of NADH. However, by multiplying by 3, the number of electrons transferred is multiplied by 3. Reaction 2 and 3 belong to the same set of redox reactions; whatever electrons reaction 2 loses is the same # of electrons that reaction 3 gains. So reaction 3 must be multiplied by 3 to match the same # of electrons transferred.