glycolysis Flashcards
What is the main objective of glycolysis?
generation of ATP
where are glycolytic enzymes found?
in the cytosol
tissues of the eye and RBCs can only obtain their ATP from where?
glycolysis
recite glycolysis with the enzymes. what are the mnemonics you like?
good golly father Franklin did go by picking pumpkins to prepare pies
enzymes: hungry Peter Pan and giring pink panther eat pies
what are the energy investment phases of glycolysis?
glucose—glucose 6 phosphate
fructose 6 phosphate to fructose 1,6 bisphosphate
enzymes= hexokinase/glucokinase
PFK1
paid 2 atp
What is the energy generation phase?
2 NADH formed after G3P
at enzymes: g3p (NADH)
dehydrogenase
phosphoglycerate kinase ATP
pyruvate kinase ATP
ATP formed after bisphosphoglycerate
ATP formed after phosphoenolpyruvate
what are the three irreversible enzymes of glycolysis?
hexokinase/glucokinase, PFK1 and pyruvate kinase
what enzyme turns DHAP dihydroxyacetone phosphate into G3P?
trios phosphate isomerase
How many pyruvate as a result of glycolysis?
2 3 carbon molecules
what steps have substrate level phosphorylation?
phosphoglycerate kinase and pyruvate kinase
what enzyme turns pyruvate to acetyl coa?
pyruvate dehydrogenase in mitochondria in aerobic glycolysis goes to TCA cycle
what enzyme turns pyruvate to lactate?
lactate dehydrogenase in anaerobic glycolysis in cytosol and goes to liver via cori cycle
in tissues with no mitochondria like RBC and eye
In the liver what enzyme converts pyruvate to oxaloacetate?
pyruvate carboxylase for gluconeogenesis in the liver.
occurs in mitochondria
What enzyme turns NADH made by G3P dehydrogenase into NAD+?
NADH–NAD
this NAD is used at
Pyruvate __lactate dehydrogenase____ make lactate
in RBC and skeletal muscle
the conversion of pyruvate to lactate depends on what cofactor?
NADH
when there is cardiac muscle hypoxia what does it produce?
lactate= myocardial infarction sign
what is cori cycle?
lactate goes to blood then liver and back to glucose via gluconeogenesis and that glucose gets sent into the muscle. its a whole cycle
How many ATP per NADH
3 ATP there is 6 from glycolysis
What transports NADH made in the cytosol to the mitochondria for kreb?
malate aspartate/ glycerol phosphate shuttle
how many ATP in aerobic glycolysis?
8 atp
glucose is converted into how many molecules of lactate for anaerobic glycolysis?
2
how much energy formed with anaerobic glycolysis?
2 ATP formed
what is the mechanism of transport of glucose into RBCs?
facilitated diffusion via GLUT1
GLUTS don’t require energy
where does GLUT 2 move to?
the liver
GlUT 1 and 3 moves to where?
neurons and brain
GLUT 4 in the adipose tissue and muscle is responsive to what?
presence of insulin when blood glucose is elevated
where is glucokinase found?
liver and b-cells of pancrease
what is the affinity for glucokinase in liver and pancreases?
has a high km and small affinity ( graph on left)
hexokinase is found where?
other tissues except pancreas and liver; has low km high affinity.
lower v max
what happens when there is too much NADH/NAD ratio and there a high lactate level?
you can get cramps because of very low PH
What are inhibitors of glycolysis?
fluoride inhibits it, it inhibits enolase
2 phosphpglycerate to phosphoenolpyruvate
what energy supply to tumors use? what is this called?
Warburg effect; glycolysis
red blood cells have what kind of conditions
anaerobic they are major source of ATP and make 2,3 bisphosphoglycerate
what is PET( positron emission topography) scan used for ?
you can isolate where a tumor is because they like to take up glucose… in this the glucose analog Is FDG or fluorodeoxyglucose.
in image it has a lot of light= its proof that tumor Is taking it up
what forms 2,3 bisphosphoglycerate?
from 1,3 bisphosphoglycerate use a mutase to make it.
instead of a phosphoglycerate kinase to make 3 phosphoglycerate
2,3 bpg does what?
reduces affinity of oxygen for hemoglobin to unload more oxygen to tissues
Deficiency of what enzymes result in hemolytic anemia?
hexokinase or pyruvate kinase deficiency
if there is an issue of glycolysis what happens?
sodium potassium atpase doesn’t work.
accumulation of sodium, lysis of RBC/hemolysis
what is the #1 cause of hemolytic anemia?
g6pd deficiency
what is the #2 cause of hemolytic anemia?
erythrocyte pyruvate kinase deficiency
How do you examine someone with pyruvate kinase deficiency?
you check 2,3 bisphosphoglycerate and you will find that they are elevated
what happens with hexokinase deficiency?
2,3 bpg is low… this is more severe than pyruvate kinase deficiency
what is the cause of hemolysis ?
less atp and less working of sodium potassium pump
if there is high AMP then glycolysis is…
activated
if there is high levels of ATP then glycolysis is….
deactivated
