Glucose Regulation in Muscle

Question 1

___/____ inhibits ____ and ____ when muscle is relaxed

Glucose-6-P _______ the enzyme _____ during relaxation

Answer 1

high-ATP/low-AMP inhibits PFK & PyruvateKinase

Glucose-6-P inhibits Hexokinase when m. relaxed

Question 2

___/____ stimulates ___ during contraction

_____ stimulates pyruvate kinase during contraction

Answer 2

low-ATP/-high-AMP stimulates PFK

Fructose 1,6 Bisphosphate

Question 3

Liver PFK activation

Answer 3

Fructose-6-Phosphate —> Fructose 2,6 Bisphosphate –> activates PFK

Question 4

insulin does what to PFK

Answer 4

activates Protein kinases to dephosphorylate PFK-2
this increases F2,6BP
F2,6BP stimulates PFK-1

Question 5

glucagon does what PFK

Answer 5

activates cAMP
cAMP activates PKA to phosphorylate PFK-2
this causes PFK2 to lower F26BP
lowered F26BP lowers activity of PFK-1

Question 6

insulin does what to Pyruvate Kinase

Answer 6

insulin activate protein phosphatases to activate PK

Question 7

Glucokinase regulation

Answer 7

low levels of glucose cause Fructose-6-Phosphate to stimulate GK translocation to the nucleus where it is inhibited through binding of GK-regulatory protein

high levels of blood glucose cause the opposite