Glucose/Insulin Flashcards
GLUT2 location
Beta cells
Liver
Intestine
GLUT 4 Location
Adipose tissue
Skeletal muscle
Heart
GLUT3 location
Brain
Glucokinase action
Converts Glucose to glucose-6-phosphate
Glucokinase features
Not inhibited by substrate (glucose-6-phosphate) so keeps working when glucose is high
Low affinity for glucose so only active when glucose is above normal levels (too high)
What happens when insulin is released?
It binds Insulin receptor, an RTK, causing dimerisation and auto-phosphorylation of tyrosine residues
What happens when RTK is activated
Binding and phosphorylation of adapter protein IRS, which PI3K then binds to, acitvating it
What does PI3K do
Phosphorylates PIP2 to PIP3
What does PIP3 do
Activates AKT
What does AKT do
Causes GLUT4 translocation to the membrane, allowing glucose influx via facilitated diffusion
What happens to glucose-6-phosphate once it is formed
Converted to pyruvate and ATP
What does ATP then do
ATP binds ATP-dependent K+ channels, closing them, causing membrane depolarisation and Ca2+ influx
What does Ca2+ influx cause
Insulin-containing granules to be released
HBA1C
Long term glucose measure using RBCs
Shows 2-3 month history
Anti-GAD
Autoantibody
Serum marker for T1DM
