Review Flashcards
What does epinephrine influence, and where?
Activates glycogen phosphorylase in muscle
What does glucagon do, and where?
Activates glycogen phosphorylase in the liver–also activates cAMP-dependent PKA
What does insulin do and where?
Activates glycogen synthase in both muscle and liver–also activates protein phosphatases
Where is insulin produced?
beta cells of the pancreas
Where is glucagon produced?
alpha cells of pancreas
how is insulin secreted?
ATP from glycolysis inhibits Na-K ATPase pump, causing membrane to depolarize (K leaves)–membrane pot. change causes Ca2+ channels to activate; the Ca that enters and that which is released from the ER causes insulin to be secreted from the cell
What transporter is regulated by insulin?
GLUT4 (glucose transporter)
Where is glut4 found?
only in muscle and adipose tissue
glucagon mostly affects liver tissue with a bit of adipose, but insulin affects liver, adipose, and muscle
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What pathways does F2,6BP regulate?
Activates glycolysis (activates PFK-1) and inhibits gluconeo (inhibits FBPase-1)
What is unique about FBPase-2 and PFK-2 activities?
they are in the same enzyme
covalent modification of PFK-2/FBPase 2
when dephos, PFK-2 activity is active; when phos, phosphatase (FBPase-2) activity is
since F2,6BP activates glycolysis, glucagon inhibits the creation of F2,6BP by phosphorylating the enzyme so FBP-ase activity is active
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How is PKL regulated?
inhib by glucagon, activated by insulin–active=dephos, inactive=phos
describe regulation of PEPCK and G6Pase
inhib by glucagon, act. by insulin–insulin binds to insulin receptor
