Now, what is a divalent metal atom? Well, it's a metal atom that can gain a positive charge, a charge of positive two. So he can lose two electrons and gain a positive charge of two. And two types of atoms that work in this particular case are magnesium so, Mg and Manganese MN. And the reason we need this metal atom is because it acts as a cofactor, it increases the efficiency of this enzymes activity. Now let's take a look at the following diagram that basically describes in detail how that bond is formed.