On the other hand, if Km is low, this ratio is high. And so v not is high. And so if Km is low, that means the affinity for that substrate and active site is high. And so that substrate will be able to spend enough time to catalyze it into that product. And likewise, if Kcat is high, that means this ratio is high and this velocity will be high. So we see that ultimately, the ratio of Kcat divided by Km, which is the rate constant in this reaction here, basically can be used as a measure of how well that enzyme actually catalyzes that particular substrate.