Flashcards in 2017 Biochemistry - Glycolysis Deck (20):
Reactants and Products of Hexokinase/Glucokinase - Step 1?
Glucose + ATP -> G6P
Reactants and Products of Phosphofructokinase - Step 3?
Fructose-6-P + ATP -> Fructose-1,6-bisphosphate
Reactants and Products of Pyruvate Kinase - Step 9?
Phosphoenolpyruvate + ADP -> Pyruvate + ATP
Which steps of Glycolysis produce ATP?
Step 6 & 9
Phosphoglycerate kinase and Pyruvate Kinase
Which steps of Glycolysis use ATP?
Step 1 & 3
Hexokinase/Glucokinase and Phosphofructokinase
What are the 3 enzymes responsible for the irreversible steps of Glycolysis?
Hexokinase/Glucokinase - step 1
Phosphofructokinase - step 3
Pyruvate kinase - step 9 & final step
Differences/Similarities between Hexokinase and Glucokinase?
Glucokinase - present only in liver, kidney and B cells, low affinity = function is to remove glucose from blood following a meal, not inhibited by G6P.
Hexokinase - present in all tissues, very high affinity = saturated under normal condition and acts as a constant rate, Inhibited by G6P
Aerobic Glycolysis; products, ATP produced, shuttle system
-Pyruvate is converted to acetyl-CoA in mitocondria for TCA cycle
-Oxidation of ACoA will lead to 36 ATP produced
-Under aerobic conditions NADH which is produced may be re-oxidized by mitochondria through a shuttle system.
Primary purpose of Anaerobic Glycolysis?
To regenerate NAD+ using the G3P shuttle.
This allows NADH equivalents to get out of the mitochondria.
Pyruvate is reduced to Lactate
What are the inhibitors of Hexokinase?
What are the Activators/Inhibitors of PFK-1?
Activators: F-2,6-bP, AMP
Inhibitors: Citrate, ATP
What are the Activators/Inhibitors of Pyruvate Kinase?
Activators: F-2,6-bP, AMP
Inhibitors: Acetyl-CoA, ATP
What enzyme is used in Erythrocytes to bypass the "normal" route from Glyceraldehyde-3-p --> 3-Phosphoglycerate, which product is made in place of 1,3-bPG and what is it's importance?
2,3-bPG is made in RBCs which binds to Hb and decreases it's affinity for O2, thus freeing O2 for use in tissue.
What are the 3 enzymes important to fructose metabolism?
Fructokinase: Fructose + ATP -> Fructose-1-p
Adolase B: Fructose-1-p Glyceraldehyde + Dihydroxyacetone phosphate
Triose Kinase: Glyceraldehyde + ATP -> Glyceraldehyde-3-phos.
Which enzyme of fructose metabolism is blocked in Essential Fructosuria?
Which enzyme of fructose metabolism is blocked in Hereditary Fructose Intolerance?
Galactose metabolism: important enzymes and resultant product
2. UPD-Glc:Gal-1-P uridylyltransferase
Results in Glucose-6-P production
Which enzyme is lacking/faulty in Galactosemia?
Mannose metabolism: important enzymes and resultant products
Mannose Kinase (liver) converts mannose to Mannose-6-P
Phosphomannose isomerase catalyzes Mannose-6-P to F-6-P