And why is that useful? Well, it's useful because hydroxide ions are very, very potent nucleophiles. And so what that means is, once we form that hydroxide, it'll be much more likely to actually attack the carbon of that carbon dioxide to ultimately form that bicarbonate ion. And to see what we mean, let's take a look at this reaction mechanism that takes place inside the active side of carbonic and hydrates. So in the first step, we essentially form this complex that consists of the water molecule bound onto that zinc. So what happens is the oxygen of this water contains a partial negative charge because, remember, it's more electronegative than either one of these H atoms.