So we transfer of a spoil group from the ATP onto this bicarbonate to form this carboxy phosphate. And the reason we have to carry this step out is to actually prepare that molecule to bind that CO2 molecule onto that biotin because without this step, the CO2 would simply not be able to bind onto that binding site of that enzyme. So once again, recall that carbon dioxide exists as bicarbonate ions in the cytoplasm and in our fluids of the body. And in the first step of this process, we essentially use an ATP molecule to activate the carbon dioxide to form the carboxy phosphate. This is our carboxy phosphate complex. And so we form the ATP that we have here on the product side.