The second messenger in the following G-protein-linked-receptor pathway is signal moleculeG protein linked receptor activated G protein adenylate cyclase - > CAMP Select one: a. signal molecule b. activated G protein c. adenylate cyclase d. CAMP

Answer is D - cAMP.

Explanation:

cAMP is a small molecule that functions as an intracellular signaling molecule - a second messenger. The first messenger would be the thing that activated the GPCR (e. g. a hormone). The GPCR is a signal transducer (converts extracellular signal to intracellular signal). Once activated, the GPCR activates adenylate cyclase which can be called a signal effector - it is an enzyme that produces cAMP.