Glucose Metabolism Step One

Question 1

GLUT1

Answer 1

found mostly in RBCs and BRANI

Question 2

GLUT2

Answer 2

found mainly in liver, low affinity with no regulation

Question 3

GLUT3

Answer 3

main transporter in liver

Question 4

GLUT4

Answer 4

skeletal muscle, heart, adipost

insulin dependent

Question 5

Step 1 glycolysis

Answer 5

Glucose—> Glu-6-Phos –> Fructose–6–P –> Fructose–1,6–Bisphos

Hexokinase catalyzes Glu-6-P: First Phosphorylation event
Phosphosglycerate Isomerase: Catalyzes rearrangement of Glu-6-Phos —> F6P
Phosphofructokinase catalyzes F6P–>F-1,6-Bisphosphate: second phosphorylation event

Phosphorylation by hexokinase (ATP–> ADP)
Isomerization by Phosphoglucose Isomerase
Phosphorylation by Phosphofructokinase

P–Isom–P events
2 ATP spent

End product: F-1,6-Bisp

Question 6

Which events in step 1 of glycolysis are irreversible?

Answer 6

first and third

Question 7

+/- @ step 1: all cell types

Answer 7

build up of glucose-6-P neg inhibits step 1

Question 8

+/- @ step 1: liver, pancreatic beta cells

Answer 8

+stim: glucose, Fructose-1-P, insulin

-stim: Glucagon, Fructose-6-p

Question 9

+/- @ step 3

Answer 9

+stim: AMP, fructose, (2,6)Bisphos

-stim: ATP, Citrate