pyruvate dehydrogenase and citric acid cycle Flashcards
where are PDH and TCA located?
in the matrix of mitochondria
what is the purpose of pyruvate dehydrogenase for the TCA cycle?
to make pyruvate so that it can be converted to acetylcoA
What is the main structure in the cell that produces ATP?
the mitochondria/ power plant
What is the purpose of the TCA cycle?
to produce energy
what are the fates of pyruvate?
lactate, oxaloacetate, alanine, acetyl CoA
what is the process called when pyruvate forms alanine?
transamnation-transfer ofone amino group to another
what is the process called that allows for pyruvate to be transfered into oxaloacetate?
carboxylation
when pyruvate is oxidized and decarboxylated what does it form?
Acetyl CoA
when pyruvate is reduced what is formed?
lactate
how is acetyl CoA oxidized further?
it enters the TCA cycle
what are some important intermediates in the TCA cycle that can be derived from other process?
Succinyl CoA, Oxaloacetate, Fumarate, alpha ketoglutarate
what are the two reasons that pyruvate dehydrogenase is important?
because it is the link between glycolysis and the kreb cycle and it also provides us with energy
what are the three catalytic enzymes for the pyruvate dehydrogenase complex?
pyruvate dehydrogenase, dihydrolipoyl dehydrogenase, and dihydrolipoyl transacetylase
what are the regulatory proteins involved in the pyruvate dehydrogenase complex?
protein kinase(phosphorylation) and protein phosphatase (dephosphorylation)
what are the 5 coenzymes in the pyruvate dehydrogenase complex?
CoAsh, FAD, NAD, thiamine pyrophosphate (TTP), lipoic acid
is PDH only found in the mitochondrial matrix?
YES
in the PDH complex, pyruvate is decarboxylated by pyruvate dehydrogenase and transfers what group to the acyl carrier ?
transfers the acetyl group to pyrintriphosphotase (acyl carrier)
after being transfered to pyrintriphosphate the acetyl group is then phosphorylated to
acyl lipoate (Dihydrolipoyl transacetylase- acetyl carrier)
what does acyl lioate get converted to ?
CaAsh to acetyl CoA
when lipoic acid is reduced, the electrons can be oxidized to and will transfer its elecrtrons to?
FAD–> FADH2
after FADH2 is formed from getting electrons from the oxidized lipoic acid what will it do with these electrons?
it passes them yo NAD+ to NADH (electron carries dihydrolipoyl dehydrogenase)
what activates PDH?
dephosphorylation, insulin in adipocytes and liver, catecholamines in cardiac muscle, calcium in skeletal muscle
what inhibits PDH?
phosphorylation, acetyl CoA, ATP, NADH
is PDH activated when it is phosphorylated?
no it is inactive
what would be needed to activate the phosphorylated PDH?
PDH phosphotase
how is PDH phosphotase activated?
by Ca+ and Mg+2
what are NADH, ATP, ACETYL-CoA used for in the PDH complex?
PDH kinase
how many acetyl CoA’s will go into the TCA cycle?
2
what are the two amino acidsthat can form acetyl CoA?
leucine, lysine
what are the three fates of acetyl CoA?
tricarboxylic acid cycle, ketone bodies, sterols- fatty acids
howmany carbons does citrate have?
6
in the kreb cycle, what happens with cisaconitrate and isocitrate?
isomerization
with isocitrate to oxalosuccinate when using isocitrate dehydrogenase what happens that is important here?
the first electron accepted ( NAD+ to NADH+H+)
from oxalosuccinate to alpha keto glutarate using isocitrat dehydrogenase what is lost?
the first carbon is lost by way of carbon dioxide
from alpha keto glutarate to succinyl CoA, what happens here?
the second carbon is lost andthe second NADH to NAD+ occurs
from succinyl CoA to succinate how many carbons do you have?
4
what is formed when succinyl CoA synthetase is used to transfer succinly CoA to succinate?
GTP
when succinate is changed to fumarate by succinate dehydrogenase what happens here?
FAD forms FADH
from fumarate to L malate what enzymeis used?
fumarase
from L-Malate to oxaloacetate by malate dehydrogenase what happens here?
the last electron transfer exchange of NAD+ to NADH happens
when oxaloacetate accepts acetyl CoA into the kreb/citrate cycle what does it form?
citrate(6 carbon sugar)
what changes oxaloacetate to citrate?
citrate synthetase
what enzymes aid in the process of NAD to NADH?
isocitrate DEHYDROGENASE, a-ketogltarate DEHYDROGENASE, malate DEHYDROGENASE
What enzyme aids in FAD to FADH?
succinate DEHYDROGENASE
When is GTP formed with what enzyme?
succinyl CoA synthetase
where are the two carbons relased?
isocitrate dehydrogenase, and alpha ketoglutarate dehydrogenase
How may times is H2O fed in this cycle?
3, before and after aconitase, and at fumarase
How much ATP is made in the kreb cycle?
2atp/ acetyl coA oxidized but since 2 then it is 24 ATP
3 NADH (9 ATP) 1 GTP (1 ATP) 1 FADH2 (2 ATP)
what are the 2 diseases that are caused by thiamine deficiency?
werneke-korsakoff syndrome, and wet beri beri
