I' ll be wildly optimistic and assu

I' ll be wildly optimistic and assume that you remember a thing or two about nucleic acids, so wewill mostly skip this topic.Nucleotides are very important as cosubstrates in metabolism. As you know, ATPoccurs everywhere, butGTP, CTP, and UTP drive some biochemical reactionsas well.Adenosine and adenine nucleotides also function as signaling molecules; for example, ADP is important inthrombocyte activation. Caffeine is an antagonist atadenosine receptors, which tells us that adenosine isimportant in the regulation of vigilance. Cyclic AMP and cyclic GMP functionas intracellular second messengers.