Question

Glucagon is a hormone that is released when the level of glucose in the blood is low. Glucagon uses a G protein signaling pathway to promote glycogenolysis. Put the steps of the signal transduction pathway in order from the releasing of glucagon into the blood to the promotion of glycogenolysis. Glucagon is released into blood.

Answer 1

NOTE: the steps of the signal transduction pathway to be arranged is in the attached file.

Answer:

The correct signal transduction pathway in order from the releasing of glucagon into the blood to the promotion of glycogenolysis includes:

- Glucagon binds extracellulary to G- protein coupled receptor.

-G protein releases GDP and binds FTP

-Activated G protein activates adenylate (adenylate) cyclase.

-Adenylate cyclase converts ATP to cAMP.

-Cyclic AMP activates protein kinase A

- phosphorylase kinase phosphorylates glucogen phosphorylase, an enzyme needed for glycogenolysis.

Explanation:

As carbohydrates from food consumed is digested, it's end product, the glucose, is assimilated into the cells for energy production through the help of insulin in a process called glycolysis. Excess of glucose is stored in the liver as GLYCOGEN.

In cases where there is reduced sugar in the blood (hypoglycemic state) another pathway (known as glycogenolysis through

GLUCAGON hormone) is initiated to elevate the concentration of glucose in the blood.