Glucose/Glycolysis/Gluconeogenesis

Question 1

Glycolysis ATP Production per Glucose (2)

Answer 1

32 net ATP via malate-aspartate shuttle (heart and liver), or 30 net ATP via glycerol-3-PO4 shuttle (muscle)

Question 2

Hexokinase vs. Glucokinase (location/affinity/Km/Vmax)

Answer 2

Hexokinase is in most tissues, whereas glucokinase in liver and Beta cells of pancreas (so Insulin regulation). Heoxkinase has a much higher affinity for glucose, so a lower Km, but a lower Vmax. Glucokinase has a lower affinity for glucose so a higher Km, but a higher Vmax. Glucokinase is also induced by insulin

Question 3

2 Stimulators and 2 Inhibitors of PFK-1

Answer 3

S: AMP, F2,6Bisphosphate
I: ATP, Citrate

Question 4

1 Stimutor and 2 Inhibitors of Pyruvate Kinase

Answer 4

S: F1,6bisphosphate
I: ATP, alanine

Question 5

Glycolysis Enzyme Deficiency (usually Pyruvate Kinase)

Answer 5

RBCs can’t maintain Na/K gradient so get HA

Question 6

Regulation by Fructose 2,6 Bisphosphate

Answer 6

PFK-2 (active fed) converts F6P into F2,6P which stimulates PFK-1 converting F6P into F1,6P
FBPase-2 (active fasting) converts other direction back to F6P and towards gluconeogenesis

Fasting: Glucagon stims cAMP activates PKA activates FBPase-2/inhibits PFK2 so get less glycolysis and more gluconeogenesis
Fed: Insulin inhibits cAMP and PKA so inhibit FBPase2/activate PFK2, increasing glycolysis and inhibiting gluconeogenesis

Question 7

4 Irreversible Enzymes in Gluconeogenesis

Answer 7

Pyruvate carboxylase (pyruvate-OAA)
PEP Carboxykinase (OAA-PEP)
Fructose 1,6 Bisphosphatase (F1,6BP into F6P)
Glucose-6-Phosphatase. The one that muscles and shit lack

Question 8

1 Stimulant and 1 Inhibitor of Fructose 1,6 Bisphosphatase

Answer 8

S: Citrate
I: Fructose 2,6 bisphosphate