And what we want to do is we want to attach another sugar, let's say a glucose molecule, onto that red sugar. So this is the purple glucose that we want to attach onto that sugar molecule. Now, before the glycosyl transferase can actually catalyze this reaction, what we have to do is we have to activate this incoming glucose molecule. So we have to activate it, we have to make it more reactive. And the way that we make it more reactive is we add a nucleotide component onto this glucose. Now, how exactly does that make it more reactive?