Substance C is secreted from a neuron, and binds to its receptor on a nearby cell, triggering an increase in intracellular cAMP. Substance C is therefore a ligand for a ____.
A) a receptor tyrosine kinase
B) a G-protein-coupled receptor
C) a hormone receptor
D) a ligand-gated ion channel
E) guanylyl cyclase

Question

Quizplus · Accepted Answer

Substance C acts by binding to its receptor and triggering an increase in intracellular cAMP, which is a common pathway for G-protein-coupled receptors (GPCRs). GPCRs activate a G protein, which then activates adenylyl cyclase, leading to an increase in cAMP.

Substance C Is Secreted from a Neuron, and Binds to Its