Now in this particular case, because I'm using ATP as a specific nucleuside triphosphate, the name of the NMP kinase molecule is adenylate kinase. And so adenylate kinase will catalyze the transfer of this purple terminal phosphoryl group from the ATP molecule onto this region of the nucleocide monophosphate and we ultimately form the nucleocide diphosphate and the adenosine diphosphate. So this loses a phosphoryl group and this gains a phosphoryl group. So in this reaction we have two substrate molecules, the ATP as well as the MMP. Now what do we have to know about nucleotide monophosphate kinases? Well, there are three things that you have to keep in mind about these enzymes and let's begin by discussing the first one.