First and second messengers

What is the first messenger?

The hormone that brings the info/signal from the endocrine gland and they bind to receptors on cell surface membranes (adrenaline)

What is the second messenger?

cAMP, inside the cell which causes the effect

What is the first step in the mode of action for adrenaline?

Adrenaline is an amino acid derived hormone released by the adrenal glands into the bloodstream. It’s target cells have complementary shaped receptors on their plasma membranes

What is the second step in the mode of action for adrenaline?

Receptors are associated with adenylyl cyclase which changes shape and activates when adrenaline binds to it

What is the third step in the mode of action for adrenaline?

Activated adenylyl cyanide catalyses the conversion of ATP to the second messenger molecule, which is cAMP

What is the fourth step in the mode of action for adrenaline?

cAMP binds to protein kinase A enzymes which activates them

What is the fifth step in the mode of action for adrenaline?

Activated protein kinase A enzymes initiate a series of enzyme activations, resulting in the breakdown of glycogen to glucose

What does this enzyme cascade do?

amplifies the original signal from adrenaline and results in the result of extra glucose by the liver to increase the blood glucose conc