Can anyone tell me about cyclic AMP, its function in human and bacteria, application
General speaking, cAMP is a second messenger that "amplifies" a variety of signaling process. You can look at the following link for entry knowledge...
Your question is very general and one could talk about the topic for a very long time. In very general terms, cAMP is part of a second messenger system (like the IP3/PKC, lipoxygenase, cGMP, NO synthetase systems). The reason why organisms have these systems is because many water soluble hormones cannot cross cellular membranes, so they use these secondary messenger to carry their signal to downstream effectors. The actual function is as varied as there are activities in an organism.
Hmm, what i wish to know is what has been done base on the knowledge of cAMP in realife, or the application of cAMP concept in real life..