Flashcards in B2.045 Prework 1 Biological Differences of GLUT Isoforms Deck (8)
how do GLUT 1-4 and GLUT 5,7 differ?
GLUT 1-4 stereo-selective for glucose
GLUT 5,7 stereo-selective for fructose
characterize GLUT 1-4
passive, facilitated diffusion requires sugar gradient
how does GLUT appear to function?
alternating conformations between cytoplasmic and extracellular facing modes
why do we think GLUT has alternating conformations?
alternative drugs can block the two different protein sites
how do the 12 GLUT isoforms differ?
where is GLUT2 located?
liver, islets, kidney, small intestine
why is the GLUT2 Km so high compared to normal circulating glucose in the small intestine? (17 mM vs. 5 mM)
this makes GLUT2 more useful in the fasting state and prevents the channel from running backwards from blood into cell