When glucagon binds to its receptors on the surface of adipose tissue, it activates a signaling cascade leading to the release of free fatty acids that can be utilized by the liver and other peripheral tissues for energy production. Which of the following is the correct nucleic acid involved in the triggering of this cascade?
A) ATP
B) cAMP
C) cGMP
D) GTP
E) xanthine

Question

Quizplus · Accepted Answer

cAMP (cyclic adenosine monophosphate) is the second messenger involved in the signaling cascade triggered by glucagon binding to its receptor, leading to the activation of protein kinase A and subsequent release of free fatty acids.  Glucagon binds to plasma membrane receptors coupled through a G-protein that activates adenylate cyclase. Adenylate cyclase generates cAMP from ATP and the resultant increases in cAMP in turn activate cAMP-dependent protein kinase, PKA. Activation of PKA leads to increased fatty acids release from triglycerides stored in adipose tissue.

When Glucagon Binds to Its Receptors on the Surface of Adipose