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Quizbowl science/Biology/Glucagon
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
Glucagon is a GPCR. It is released from the alpha cells of the Islets of Langerhans of the pancreas.https://www.youtube.com/watch?v=1ImdVTWKiqs&list=PLmGAunhTA6--y7K04aQx1ZKhEuc-gsQIl&index=79
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