And the aldohexos that we're going to use as our prototypical example is glucose, more specifically, the D glucose. So remember, the de glucose simply means this blue hydroxyl group found on the last stereogenic carbon. Carbon number five points to the right side and not to the left side. Now, what basically happens is an intramolecular nucleophilic reaction takes place in which the hydroxyl group, the oxygen of the hydroxyl group found on the fifth carbon, basically attacks nucleophilically, the carbon of this carbonyl that is part of this aldehyde group, and we form this bond. And that bond is shown in purple here as well as here. Now, why did I draw two different molecules, A and B?