Glucose Transporters

Question 1

Glucose transport

Answer 1

Too big to diffuse: use

Na/ATP dependent cotransport
Na/ATP independent transport

Question 2

Sodium and ATP dependent cotransport

SGLT

Answer 2

Moves glucose up gradient and sodium down
Gradient created by Na/K pump

Intestine, renal tubes, choroid plexus (BBB)

Question 3

Sodium and ATP independent transport

Answer 3

Passive system mediated by GLUT transporters (uniporters, change conformational states)

Question 4

GLUT Transporters

Answer 4

Rude Lobsters Barely MAke It

GLUT1: RBC, BBB
GLUT2: Liver, kidneys, beta cells
GLUT3: Brain (neurons)
GLUT4: Muscle and Adipose (can be increased by insulin)
GLUT5: Intestinal epithelium and Testes

1,3,4 involved in glucose uptake from blood
2 responds to glucose levels to take in or push out
5 can transport fructose and glucose

Question 5

GLUT 2 deficiency

Answer 5

Fanconi Bickel syndrome
Disorder of glucose homeostasis

Accumulation of glycogen in liver and kidney, failure to export glucose and inhibits glycogen degradation

Question 6

Insulin and GLUT 4

Answer 6

Insulin moves GLUT4 transporters to membrane
Exercise increases expression of GLUT4
Contraction can recruit GLUT4 to membrane

Question 7

Dehydration and SGLT

Answer 7

SGLT transporters found in jejunum
Water follows Na and glucose, rehydrates blood stream

Severe dehydration: give water with Na and glucose to rapidly pull water into vascular system