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: Results in lower F-2,6-BP:
 * inhibits PFK-2 -- less F-2,6-BP made
 * activates FBPase-2 -- more F-2,6-BP degraded
 * allosterically activates FBPase-1 -- increased gluconeogenesis (more glucose)
 * less active PFK-1 -- decreased glycolysis

==Sources