Flashcards in carbohydrate metabolism I Deck (10)
GLUT2 (only in cells and are highly regulated)
GLUT4 (only in cells and are highly regulated)
low affinity transporter in hepatocytes and pancreatic cells.
captures glucose for storage
is in adipose tissue and muscle and responds to glucose concentration in peripheral blood.
insulin increases the rate of glucose being transported between the adipose tissue and the muscle
Km is close to normal glucose levels (~5mM)
Which means that the transporter is saturated when blood glucose levels are just a bit higher than normal
a lot of insulin = increases GLUT4 transporters available
a decrease in insulin = decreases the amount of GLUT4 transporters available
occurs in the cytoplasm of all cells, and does not require oxygen
yields 2 ATP per molecule of glucose
converts glucose to glucose 6 - phosphate
Present in the pancreatic beta - islet cells as part of the glucose sensor and is responsive to insulin in the liver
converts glucose to glucose 6 - phosphate in peripheral tissues
Phosphofructokinase- 1 (PFK-1)
phosphorylates fructose 6-phosphate to fructose 1,6-bisphosphate in the rate limiting step of glycolysis.
PFK1 is activated by AMP and fructose 2,6-bisphosphate (F2,6-BP) and is inhibited by ATP and citrate
Phosphofructokinase- 2 (PFK-2)
produces the F2,6-BP that activated PFK-1.
It is activated by insulin and inhibited by glucagon
produces NADH, which can feed into the electron transport chain