krebs Flashcards
justify krebs cycle is also anabolic
as it provide intermediates for important anabolic reactions, such as glucose formation from carbon skeletons of some amino acids and the synthesis of some amino acids
what is the major source of acetyl coA for TCA cycle ?
oxidative decarboxylation of pyruvate by PDH complex
where does the oxidative decarboxylation of pyruvate by PDH complex happen?
in the mitochondrial matrix
what is the sources of acetyl coA?
oxidative decarboxylation of pyruvate
Fatty acid oxidation
what is the components of PDHC enzyme?
protein aggerate of multiple copies of three enzyme
E1 names
pyruvate decarboxylase
pyruvate dehydrogenase
E2 name
dihydrolipoyl transacetylase
E3 name
dihydrolipoyl dehydrogenase
what is PDHC regulatory enzymes
pyruvate dehydrogenase kinase
pyruvate dehydrogenase phosphatase
what does PDHC consist of?
3 enzymes
2 regulatory enzymes
5 co enzymes
coenzymes function in PDHC
act as carriers and oxidants for the intermediates in the reaction
what is the coenzyme for E1 enzyme?
thiamine pyrophosphate “TPP”
what is the coenzymes for E2 enzyme?
Lipoic acid and CoA
what is the coenzymes for E3 enzyme?
FAD and NAD+
what is the role of PDH phosphatase on E1 enzyme?
dephosphorylates and activates it
PDH kinase is activated by
ATP
Acetyl CoA
NADH
Pyruvate is potent inhibitor for which regulatory enzyme
PDH kinase
when pyruvate concentrations are elevated what would be the activity of E1
Its max activity
what inhibits aconitase
fluoroacetate
what made succinate dehydrogenase unique?
because itt is the only enzyme of the TCA cycle that is embedded in the inner mitochondrial membrane.
where did the three NADH produced?
isocitrate to alpha ketoglutarate
alpha ketoglutarate to succinyl coA
malate to OOA
3 sites of substrate level phosphorylation
2 glycolysis
1 krebs (succinyl CoA to Succinate)
the site of FADH2 in TCA
Succinate to fumarate
when did we lose the 2Co2
isocitrate to alpha ketoglutarate
alpha ketoglutarate to succinyl coA.
When we remove and add CoA
remove: OOA to citrate by citrate synthase
add: alpha ketoglutarate to succinyl coA.
