Km basically describes the situation when exactly half of all the active sites are filled with the substrate. And we'll talk much more about that in the next lecture. Now let's move on to two and three. In two and three, we basically want to show that this Mikayla's methane equation actually correctly describes this blue curve here. So let's begin by going to the beginning of that chemical reaction. So at the beginning of the chemical reaction at a time of approximately zero, we know that the substrate concentration is very, very low.