biochemistry - Tracking of oxygen molecules in glucose oxidation

For this reaction, found in typical biochemistry textbook:

$C_6H_{12}O_6 + 6O_2 \to 6CO_2 + 6H_2O$

I am interested in where do the oxygen atoms of $6O_2$ go. I think they go to $6H_2O$, but this is not sufficient for balance. So Does oxygen atom from $6CO_2$ also get into the carbon dioxide. Experimentally these can be confirmed by iostope labeling experiments. Reference to any such experiments will be appreciated.

I am interested in this question because the central metabolism can be understood as a electron transfer process where glucose is donor and oxygen is acceptor. We need to calculate, effectively how many electrons glucose transfers to oxygen in case of full oxidation.

Answer

I think this experiment (PDF file) will help you understand the basic concept about the fate of oxygen in aerobic respiration. Basically the result is:

1. The oxygen of respiratory carbon dioxide is in exchange equilibrium with body water.


2. Utilized molecular oxygen is converted to body water.

In respect to calculation of electrons donated to oxygen, just calculating how many NADH2 and how many FADH2 is reduced in how many steps during ETC will be able to answer your question.