So that we can actually store and dissolve that bicarbonate the CO2 molecule in our blood. Now, the final thing that I'd like to discuss is what we get if we take the reciprocal of the turnover number. So it turns out that if we take the K two value and we simply take the reciprocate, so we take one divided by Kcat, what that gives us is the time period that it takes a single active site of a single enzyme to actually transform a single substrate molecule into a single product. So taking the reciprocal of the turnover number gives us the time it takes to transform one substrate into one product. And so if we use this example, for instance, we get one divided by 600,000 seconds to negative one, and we see that the units are seconds because this comes on top. So what this means is 1.67 times ten to negative six of a second is the time it takes for this enzyme.