So this helper group that helps to bind that CO2. So we call this group the biotin binding domain that is used to bind the CO2 molecule and bring it into the active site of the enzyme. So basically the active side that contains that Pyruvate and we'll talk more about that in just a moment. And we also have that domain that actually binds that ATP molecule that is used to make that carbon dioxide much more active. Now, this process actually involves three individual steps, or we can call it many steps. And so these are the steps that I've listed on the board.