Glycogen metabolism Flashcards
(3 cards)
about different GLUT
GLUT 1 is found mostly throughout blood and the blood brain barrier, GLUT 3 is found more so in brain, neurons and sperm. they both have a Km of 1mM tehrefore continually transport glucose into cells at a constant rate
GLUT 2 found in liver and pancreatic beta cells. have high Km of 15-20 mM therefore have a low affinity for glucose
GlUT 4 muscle and fat cells. insulin dependant
GLUT 5 in small intestine, mainly frustose transprter
low affinity of GLUT 2
helps for glucose to only enter the liver and pancreas when it is in very high conc, only excess
why phosphorylate glucose
glucose 6 phosphate cannot pass through the clel membran edue tp the negatiev chargeds on the phosphoryl groups, and also cannot pass as it is not a substrate of glucose transporters. this allwos it not to escape from the cell even when concentrations are high in the cell. it stays in the cell for the eventual metabolism into 3c molecules with high phosphoryl transfer potential.
