glycolytic pathway!

[rjng90]

Hi I would like to ask why the answer to the question as per uploaded in the attachment below '0' and not '4'?

 

I thought if we were to start off with 2 glucose molecules and since each molecule undergo glycolysis, that means each molecule will undergo substrate level phosphorylation twice.

 

Given that the question said that one of the substrate level phosphorylation is cut off, it means there is still 1 more left. Since there are 2 ATP molecules formed per glucose molecule PER substrate level phosphorylation, shhouldnt there be a total of 4 ATP molecules produced via substrate level phosphorylation given that we have 2 glucose molecules to begin with?

 

thank you

[CharonY]

Take a detailed look at which steps ATP appears in the reaction. Look at all steps starting from glucose.

[rjng90]

i just realised i did not take into account the x2 conversion of ATP to ADP earlier which when factor into the calculation, will give an eventual answer of 0. Instead I only take into account the number of ATP produced directly from ADP which is x2 per glucose molecule.

 

So can i safely conclude that the question requires us to take into account the loss of ATP in forming ADP in the earlier parts of glycolysis? thanks

[CharonY]

indeed.