Quizbowl science/Biology/Glucagon

Glucagon is a GPCR. It is released from the alpha cells of the Islets of Langerhans of the pancreas.

Function

   #Oh no! Glucose is gone!

Glucagon responds to low glucose levels. It acts on liver cells to increase blood glucose levels by:

• inhibiting glycolysis and
• activating gluconeogenesis

Mechanism

Protein Kinase A is activated. It:

• inhibits PFK-2 -- less F-2,6-BP made
• activates FBPase-2 -- more F-2,6-BP degraded

Results in lower F-2,6-BP:

• allosterically activates FBPase-1 -- increased gluconeogenesis (more glucose)
• less active PFK-1 -- decreased glycolysis

==Sources