You are studying the activation of the enzyme adenylate cyclase in response to the addition of glucagon to myocytes in culture. You find that this activation involves the activity of a member of the G-protein family. Which of the following most closely describes the properties of this G-protein?
A) integral membrane protein
B) protein associated with the mitochondrial membrane
C) protein localized on the inner surface of the plasma membrane
D) soluble protein within the cytoplasm
E) transmembrane protein that binds a ligand at the outer surface of the plasma membrane

Question

Quizplus · Accepted Answer

G-proteins are typically localized on the inner surface of the plasma membrane where they interact with receptors and adenylate cyclase to transduce signals. The G_s family of G-proteins stimulates the activity of adenylate cyclase, resulting in increased production of cAMP from ATP. These G-proteins are localized to the inner surface of the plasma membrane in close proximity to G-protein-coupled receptors that activate the G_s protein in response to ligand binding.

You Are Studying the Activation of the Enzyme Adenylate Cyclase