Glycolysis Flashcards
Location of Hexokinase →
Most tissues, except liver and pancreatic β cells
Location of Glucokinase →
Liver, β cells of pancreas
Km of Hexokinase →
Lower (↑ affinity)
Km of Glucokinase →
Higher (↓ affinity)
Vmax of Hexokinase →
Lower (↓ capacity)
Vmax of Glucokinase →
Higher (↑ capacity)
Is Hexokinase induced by insulin? →
No
Is Glucokinase induced by insulin? →
Yes
Hexokinase is feedback-inhibited by →
Glucose-6-phosphate
Glucokinase is feedback-inhibited by →
Fructose-6-phosphate
Which enzyme catalyzes glucose to glucose-6-phosphate in glycolysis and requires ATP →
Hexokinase/glucokinase
Which enzyme catalyzes fructose-6-phosphate to fructose-1,6-bisphosphate (rate-limiting step) →
Phosphofructokinase-1 (PFK-1)
Which enzyme converts 1,3-BPG to 3-PG and produces ATP →
Phosphoglycerate kinase
Which enzyme converts phosphoenolpyruvate to pyruvate and produces ATP →
Pyruvate kinase
What activates phosphofructokinase-1 (PFK-1) →
AMP, fructose-2,6-bisphosphate
What inhibits phosphofructokinase-1 (PFK-1) →
ATP, citrate
What activates pyruvate kinase →
Fructose-1,6-bisphosphate
What inhibits pyruvate kinase →
ATP, alanine, glucagon
In the fasting state, which enzyme is active: PFK-2 or FBPase-2? →
FBPase-2
In the fed state, which enzyme is active: PFK-2 or FBPase-2? →
PFK-2
What increases in the fasting state to activate FBPase-2 and inhibit PFK-2 →
↑ glucagon → ↑ cAMP → ↑ protein kinase A
What increases in the fed state to activate PFK-2 and inhibit FBPase-2 →
↑ insulin → ↓ cAMP → ↓ protein kinase A
