Pyruvate Dehydrogenase Flashcards
What does pyruvate dehydrogenase complex (PDC) do
converts pyruvate into Acetyl CoA
Reactants of PDC
Pyruvate + NAD+ + CoASH
products of PDC
Acetyl CoA + CO2 + NADH + H+
3 enzymes in PDC
1) Pyruvate dehydrogenase
2) Dihydrolipoyl transacetylase
3) Dihydrolipoyl dehydrogenase
5 Cofactors in PDC
1) Thiamine pyrophosphate (TPP)
2) Lipoamide
3) NAD+
4) FAD
5) CoAsH
What does Thiamine pyrophosphate bind to
Pyruvate dehydrogenase (E1)
What does lipoamide bind to
dihydrolipoyl transacetylase (E2)
What does NAD+ bind to
nothing –> it’s free
What does CoASH bind to
nothing –> it’s free
what does FAD bind to
dihydrolipoyl dehydrogenase (E3)
What is Coenzyme A composed of
ADP, pentothenate (vit B5) and beta-mercaptoethylamine
how is lipoamide formed
lipoic acid is attached to a lysine R group in E2
what does lipoamide do
oxidized aldehydes to acyl groups, so acyl groups are bound to disulfide group
how does lipoamide act
like a ‘robotic arm’
what is the reduced form of lipoamide
dihydrolipoyl group
what allosterically inhibits E2
acetyl CoA
what allosterically inhibits E3
NADH
what stimulates the kinase
acetyl CoA, NADH, ATP
what inhibits the kinase
pyruvate, NAD+, ADP
