Just been revising second messengers (OCR Bio A2) with the example of cAMP in relation to adrenaline.
The book basically says that adrenaline binds to the receptor site on the cell surface membrane (first messenger), the binding causes adenyl cyclase to be activated, this converts ATP to cyclic AMP. The cAMP is the second messenger and it triggers a series of enzyme controlled reactions that have an effect.
Then, reading about the regulation of blood glucose, I found that insulin also has a similiar mechanism, where cAMP acts as the second messenger.
But the effects of adrenaline and insulin are different, and I'm guessing its not just those two hormones that use it. How does this happen when its just the cAMP activating things inside the cell in both cases?
I know I don't need to know this for the exam but I'm just curious. I was thinking it was something to do with them having possibly different target cells and different types of cells possibly having different enzymes in them for the cAMP to act upon (the idea being that cAMP wasn't that fussy with the enzymes it works on). But thats just a guess, so...yeah...
Thanks in advance for any help.
Cyclic AMP Watch
- Thread Starter
- 22-12-2010 12:37
- 22-12-2010 13:36
Hi there im on the same board as you ....and from what i have learnt from my teacher and my own curious mind is that ATP ADP cAMP are universal energy molecule (its the same molecule but with different amounts of phosphate group attached to it )
So it would led me to believe that it would start enzyme activity for adrenaline effects IE the Sympathetic nervous system
a increase in heart rate dilation of pupils etc
While Insulin would only affect the Liver ? thus cAMP would start enzyme activity for glucose concentration
A key thing you need to think about is that most reactions are universal with only subtle differences or products changing them a better example is the nervous system and how acetylchloine is unique and codes for a specific function forgot of the top of my head and if there is a different substrate then a diffrent reaction occurs but the process is largely the same ..sorry for the block of text