TBR Metabolic pathways passage 1 question 2 ???

[kgpremed11]

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Ok so the answer for this question is C. It say's Oligomycin blocks ETC and only 2 ATP's are formed. But since Oligomycin only blocks ETC, should'nt the krebs cycle still go on and there should be a net of 4 ATP? I dont see how Oligomycin stops substrate level phosphorylation.


on Question 3 right below it DOES count the 2 ATP's formed by Krebs cycle, although Oligomycin is still in use plus another inhibitor?


somebody please explain this to me?

 

[cheesier]

Since oligomycin blocks the ETC, oxygen can't be reduced so aerobic metabolism shuts down. In the second scenario, the two inhibitors combine for the net effect of blocking ATP synthase but maintaining the proton gradient so that the ETC can function, so oxidative phosphorylation stops but oxygen can still be reduced. This allows for aerobic metabolism to continue.

I don't have the book in front of me but I think this is more or less what is going on in the passage.

 

[Balantidiumcoli]

Hmm... are you forgetting the first 2 ATP that are converted to ADP? 4 ATP molecules are formed BUT 2 ATP are converted to ADP during glycolysis yielding a net gain of 2 ATP.