DAT destroyer 2014 Q 45

[panmit]

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Consider the following: ATP-->cyclic AMP. The enzyme that catalyzes this reaction is called adenylyl cyclase. This enzyme is inactive until which hormone binds?
Answer: epinephrine

But couldn't it also be Throxin, glucagon, and human growth hormone do this also. They are all peptide hormones. I searched in wiki and glucagon activates the adenylyl cyclase pathway also. I am so confused right now.

 

[Dotoday]

Hahah. You are going too deep into the pathways. Yes, what you saying is right, but looks like it is above the DAT level of difficulty. Epinephrine is what in the textbooks, which is the most common. Don't worry about memorising every single pathway.

 

[Member 139582]

Yes you are correct, I just took biochemistry, and I know that both epinephrine and glucagon's signal transduction pathways involve binding to a GPCR (G-protein coupled receptor), which activates the G-alpha protein subunit to bind to and active A. cyclase, which converts ATP --> cAMP, and cAMP is then used to activate/inactive further downstream reactions. This cascade ultimately results in glucose production, but may also lead to other products if you go more in depth, I am not specifically sure about thyroxin and human growth hormone activating the pathway, but the main pathway we learned to associate this with was epinephrine and glucagon, which leads to a production of glucose, and is probably all you need to know for the DAT.

Hope this helps!