Glycolysis Flashcards
End product of glycolysis
Pyruvate
Why is anaerobic glycolysis important
Allow cells that lack mitochondria to produce ATP
Substrate specificity of hexokinase
Broad
Hexokinase is inhibited by …
Glucose 6 pi
Km of hexokinase
Low so high affinity
Hexokinase vmax
Low
Hlucokinase is found in
Liver
Glucokinase vmax
High
Glucokinase is regulated by
Glucokinase regulatory protein which binds it when high fructose 6 pi preventing glycolysis
When glucose is high, glucokinase is free and can proceed with glycolysis
Isomerization of glucose 6 pi to fructose 6 pi done by…
Phosphoglucose isomerase
Most important control point
Committed step
And rate limiting step of glycolysis is …
Phosphofructokinase 1
PFK1 inhibited by
High ATP
High Citrate
PFK1 activated by
AMP allosterically
Fructose 2,6 biphosphate ( even when high ATP)
PFK2 produce ..
Fructose 2,6 biphosphate
What enzyme prevent activation of both glycolysis and gluconeogenesis at same time preventing futile cycle ?
Fructose 2,6 biphosphate
Well fed state ( high insulin) effect on fructose 2,6 biphosphate and glycolysis
Fructose 2,6 biphosphate increases
Glycolysis increases
Starvatation state (high glucagon) effect on fructose 2,6 biphosphate and glycolysis
Decreased fructose 2,6 biphosphate
Decreased fglycolysis
Aldo pass cleaves fructose 1,6 bishopshate to profuce ..
Glyceraldehyde 3 pi
Dihydroxyacetone
Triode phosphate isomerase inter converts…
Dihydroxy acetone to glyceraldehyde 3pi which further enhance glycolysis
Synthesis of 1,3 biphosphoglycerate done by
Glyceraldehyde 3 phosphate dehydrogenase
Biphosphoglycerate mutasse converts ..
1,3 BPG to 2,3 BPG
Phosphoglycerqte kinase converts …
1,3 BPG to 3 phosphoglycerate
Phosphoglycerate mutasse converts ..
3 phosphoglycerate to 2 phosphoglycerate
Enolase converts ..
2 phosphoglycerate to PEP (phosphoenolpyruvate)
Pyruvate kinase converts
PEP to pyruvate
Pyruvate kinase activated by
Fructose 1,6 biphosphate
Pyruvate kinase inhibited by
Glucagon which produces high cAMP which produce Pka and phosphorylation pyruvate kinase which gets inactivated
3 activities of pyruvate dehydrogenase
Oxidative decarboxylation of pyruvate -> forms acetyl coa
Carboxylation of pyruvate ( biotin dépendant) -> OAA
Reduction of pyruvate to Ethanol
Steps where ATP is used
Step one
step three
With 2 ATP used
Steps where ATP is produced
Phosphoglycerate mutase step
Pyruvate formation step
Step where NADH is produced
Glyceraldehyde 3 Phosphate dehydrogenase
Sides of the body where glycolysis is anaerobic
Red blood cells lens kidney medulla Testes Leukocytes
Why is phosphorylation of glucose important in the first step of glycolysis
Phosphorylation traps the glucose in the cytosol which commits it To be further metabolized
Main enzyme deficiency in glycolysis
Pyruvate kinase