pyruvate dehydrogenase and citric acid cycle Flashcards Preview

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Flashcards in pyruvate dehydrogenase and citric acid cycle Deck (49)
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1
Q

where are PDH and TCA located?

A

in the matrix of mitochondria

2
Q

what is the purpose of pyruvate dehydrogenase for the TCA cycle?

A

to make pyruvate so that it can be converted to acetylcoA

3
Q

What is the main structure in the cell that produces ATP?

A

the mitochondria/ power plant

4
Q

What is the purpose of the TCA cycle?

A

to produce energy

5
Q

what are the fates of pyruvate?

A

lactate, oxaloacetate, alanine, acetyl CoA

6
Q

what is the process called when pyruvate forms alanine?

A

transamnation-transfer ofone amino group to another

7
Q

what is the process called that allows for pyruvate to be transfered into oxaloacetate?

A

carboxylation

8
Q

when pyruvate is oxidized and decarboxylated what does it form?

A

Acetyl CoA

9
Q

when pyruvate is reduced what is formed?

A

lactate

10
Q

how is acetyl CoA oxidized further?

A

it enters the TCA cycle

11
Q

what are some important intermediates in the TCA cycle that can be derived from other process?

A

Succinyl CoA, Oxaloacetate, Fumarate, alpha ketoglutarate

12
Q

what are the two reasons that pyruvate dehydrogenase is important?

A

because it is the link between glycolysis and the kreb cycle and it also provides us with energy

13
Q

what are the three catalytic enzymes for the pyruvate dehydrogenase complex?

A

pyruvate dehydrogenase, dihydrolipoyl dehydrogenase, and dihydrolipoyl transacetylase

14
Q

what are the regulatory proteins involved in the pyruvate dehydrogenase complex?

A

protein kinase(phosphorylation) and protein phosphatase (dephosphorylation)

15
Q

what are the 5 coenzymes in the pyruvate dehydrogenase complex?

A

CoAsh, FAD, NAD, thiamine pyrophosphate (TTP), lipoic acid

16
Q

is PDH only found in the mitochondrial matrix?

A

YES

17
Q

in the PDH complex, pyruvate is decarboxylated by pyruvate dehydrogenase and transfers what group to the acyl carrier ?

A

transfers the acetyl group to pyrintriphosphotase (acyl carrier)

18
Q

after being transfered to pyrintriphosphate the acetyl group is then phosphorylated to

A

acyl lipoate (Dihydrolipoyl transacetylase- acetyl carrier)

19
Q

what does acyl lioate get converted to ?

A

CaAsh to acetyl CoA

20
Q

when lipoic acid is reduced, the electrons can be oxidized to and will transfer its elecrtrons to?

A

FAD–> FADH2

21
Q

after FADH2 is formed from getting electrons from the oxidized lipoic acid what will it do with these electrons?

A

it passes them yo NAD+ to NADH (electron carries dihydrolipoyl dehydrogenase)

22
Q

what activates PDH?

A

dephosphorylation, insulin in adipocytes and liver, catecholamines in cardiac muscle, calcium in skeletal muscle

23
Q

what inhibits PDH?

A

phosphorylation, acetyl CoA, ATP, NADH

24
Q

is PDH activated when it is phosphorylated?

A

no it is inactive

25
Q

what would be needed to activate the phosphorylated PDH?

A

PDH phosphotase

26
Q

how is PDH phosphotase activated?

A

by Ca+ and Mg+2

27
Q

what are NADH, ATP, ACETYL-CoA used for in the PDH complex?

A

PDH kinase

28
Q

how many acetyl CoA’s will go into the TCA cycle?

A

2

29
Q

what are the two amino acidsthat can form acetyl CoA?

A

leucine, lysine

30
Q

what are the three fates of acetyl CoA?

A

tricarboxylic acid cycle, ketone bodies, sterols- fatty acids

31
Q

howmany carbons does citrate have?

A

6

32
Q

in the kreb cycle, what happens with cisaconitrate and isocitrate?

A

isomerization

33
Q

with isocitrate to oxalosuccinate when using isocitrate dehydrogenase what happens that is important here?

A

the first electron accepted ( NAD+ to NADH+H+)

34
Q

from oxalosuccinate to alpha keto glutarate using isocitrat dehydrogenase what is lost?

A

the first carbon is lost by way of carbon dioxide

35
Q

from alpha keto glutarate to succinyl CoA, what happens here?

A

the second carbon is lost andthe second NADH to NAD+ occurs

36
Q

from succinyl CoA to succinate how many carbons do you have?

A

4

37
Q

what is formed when succinyl CoA synthetase is used to transfer succinly CoA to succinate?

A

GTP

38
Q

when succinate is changed to fumarate by succinate dehydrogenase what happens here?

A

FAD forms FADH

39
Q

from fumarate to L malate what enzymeis used?

A

fumarase

40
Q

from L-Malate to oxaloacetate by malate dehydrogenase what happens here?

A

the last electron transfer exchange of NAD+ to NADH happens

41
Q

when oxaloacetate accepts acetyl CoA into the kreb/citrate cycle what does it form?

A

citrate(6 carbon sugar)

42
Q

what changes oxaloacetate to citrate?

A

citrate synthetase

43
Q

what enzymes aid in the process of NAD to NADH?

A

isocitrate DEHYDROGENASE, a-ketogltarate DEHYDROGENASE, malate DEHYDROGENASE

44
Q

What enzyme aids in FAD to FADH?

A

succinate DEHYDROGENASE

45
Q

When is GTP formed with what enzyme?

A

succinyl CoA synthetase

46
Q

where are the two carbons relased?

A

isocitrate dehydrogenase, and alpha ketoglutarate dehydrogenase

47
Q

How may times is H2O fed in this cycle?

A

3, before and after aconitase, and at fumarase

48
Q

How much ATP is made in the kreb cycle?

A

2atp/ acetyl coA oxidized but since 2 then it is 24 ATP

3 NADH (9 ATP)
1 GTP (1 ATP)
1 FADH2 (2 ATP)
49
Q

what are the 2 diseases that are caused by thiamine deficiency?

A

werneke-korsakoff syndrome, and wet beri beri