And this bond here will be broken in step two, as we'll see in just a moment. So the important part of this step is we generate the much needed reducing agent molecule, this molecule here. We also form the Esther bond here that will be broken down in step two. So the oxidative phase begins with the dehydrogenation of the glucose six phosphate at the first carbon. So dehydrogenation simply means we're removing H ions. So an enzyme called glucose six phosphate dehydrogenase catalyzes the transfer of a Hydride ion.