Notice that the oxylosuxanate molecules don't appear any of the sides because they cancel out. So if we sum up this reaction with this reaction, this cancels out, and so does this, as well as the H plus here and H plus here. So this is the net reaction that we get on the reactant side, the isocytrate that we produce in step two and the NAD plus that acts as the carrier and picks up those two electrons that we abstract from the isocytrate, we form the NADH. The carbon dioxide molecule is removed from the isocytrate, and we form this alpha ketoglutrate molecule. Now let's move on to step four. In step four, once again, we have another oxidative decarboxylation step.