[Arait]

So, I'm extraordinarily confused by a study question our professor gave us for our test.  The question is below:

Glycolysis converts one mole of glucose into pyruvate, ATP and NADH is two phases, the conversion of glucose to triose-phosphates and the oxidation of triose-phosphates to a 3-carbon organic acid with the concomitant generation of ATP and reductant. This can be expressed in two steps as:

glucose + 2ATP --> 2GA3P + 2ADP
2GA3P+ 4ADP + 4Pi + 2NAD+ --> 2 pyruvate + 2ATP + 4ATP + 2NADH + 2H+
 added:
glucose + 2ADP + 2Pi + 2NAD+ --> 2 pyruvate + 2ATP + 2NADH + 2H+

(note that water is not shown in this expression)

a. Starting with 3 glucose molecules, write a similar equation for the conversion of glucose to pyruvate through the oxidative pentose phosphate pathway. Break the equation down into 4 steps, then balance the total equation:
i. Oxidation of glucose
ii. Conversion of oxidation products to glycolytic intermediates
iii. Conversion to GA3P
iv. Oxidation of GA3P to pyruvate, NAD and ATP
v. Balance total conversion of glucose to pyruvate through the oxidative pentose phosphate pathway
b. Which pathway produces more final energy? Explain the difference.

One of the main things that confuses me is that it keeps talking about conversion of glucose to pyruvate using the OPPP, but in my textbook and everywhere else I look the OPPP leads to ribulose 5-phosphate, not pyruvate.  Can anyone clear this up for me?  I don't know how to even begin showing this reaction when I understand what the end product is actually supposed to be...

[Yggdrasil]

Yes, the oxidative phase of the pentose phosphate pathway converts glucose into ribulose 5-phosphate.  This is what the question refers to in step (i).  The pentose phosphate pathway also contains a non-oxidative phase where ribulose 5-phosphate can be converted into fructose 6-phosphate and glyceraldehyde 3-phosphate.  This is what the question is referring to in step (ii).