pyruvate dehydrogenase and citric acid cycle

Question 1

where are PDH and TCA located?

Answer 1

in the matrix of mitochondria

Question 2

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

Answer 2

to make pyruvate so that it can be converted to acetylcoA

Question 3

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

Answer 3

the mitochondria/ power plant

Question 4

What is the purpose of the TCA cycle?

Answer 4

to produce energy

Question 5

what are the fates of pyruvate?

Answer 5

lactate, oxaloacetate, alanine, acetyl CoA

Question 6

what is the process called when pyruvate forms alanine?

Answer 6

transamnation-transfer ofone amino group to another

Question 7

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

Answer 7

carboxylation

Question 8

when pyruvate is oxidized and decarboxylated what does it form?

Answer 8

Acetyl CoA

Question 9

when pyruvate is reduced what is formed?

Answer 9

lactate

Question 10

how is acetyl CoA oxidized further?

Answer 10

it enters the TCA cycle

Question 11

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

Answer 11

Succinyl CoA, Oxaloacetate, Fumarate, alpha ketoglutarate

Question 12

what are the two reasons that pyruvate dehydrogenase is important?

Answer 12

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

Question 13

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

Answer 13

pyruvate dehydrogenase, dihydrolipoyl dehydrogenase, and dihydrolipoyl transacetylase

Question 14

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

Answer 14

protein kinase(phosphorylation) and protein phosphatase (dephosphorylation)

Question 15

what are the 5 coenzymes in the pyruvate dehydrogenase complex?

Answer 15

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

Question 16

is PDH only found in the mitochondrial matrix?

Answer 16

YES

Question 17

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

Answer 17

transfers the acetyl group to pyrintriphosphotase (acyl carrier)

Question 18

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

Answer 18

acyl lipoate (Dihydrolipoyl transacetylase- acetyl carrier)

Question 19

what does acyl lioate get converted to ?

Answer 19

CaAsh to acetyl CoA

Question 20

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

Answer 20

FAD–> FADH2

Question 21

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

Answer 21

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

Question 22

what activates PDH?

Answer 22

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

Question 23

what inhibits PDH?

Answer 23

phosphorylation, acetyl CoA, ATP, NADH

Question 24

is PDH activated when it is phosphorylated?

Answer 24

no it is inactive

Question 25

what would be needed to activate the phosphorylated PDH?

Answer 25

PDH phosphotase

Question 26

how is PDH phosphotase activated?

Answer 26

by Ca+ and Mg+2

Question 27

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

Answer 27

PDH kinase

Question 28

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

Answer 28

2

Question 29

what are the two amino acidsthat can form acetyl CoA?

Answer 29

leucine, lysine

Question 30

what are the three fates of acetyl CoA?

Answer 30

tricarboxylic acid cycle, ketone bodies, sterols- fatty acids

Question 31

howmany carbons does citrate have?

Answer 31

6

Question 32

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

Answer 32

isomerization

Question 33

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

Answer 33

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

Question 34

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

Answer 34

the first carbon is lost by way of carbon dioxide

Question 35

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

Answer 35

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

Question 36

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

Answer 36

4

Question 37

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

Answer 37

GTP

Question 38

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

Answer 38

FAD forms FADH

Question 39

from fumarate to L malate what enzymeis used?

Answer 39

fumarase

Question 40

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

Answer 40

the last electron transfer exchange of NAD+ to NADH happens

Question 41

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

Answer 41

citrate(6 carbon sugar)

Question 42

what changes oxaloacetate to citrate?

Answer 42

citrate synthetase

Question 43

what enzymes aid in the process of NAD to NADH?

Answer 43

isocitrate DEHYDROGENASE, a-ketogltarate DEHYDROGENASE, malate DEHYDROGENASE

Question 44

What enzyme aids in FAD to FADH?

Answer 44

succinate DEHYDROGENASE

Question 45

When is GTP formed with what enzyme?

Answer 45

succinyl CoA synthetase

Question 46

where are the two carbons relased?

Answer 46

isocitrate dehydrogenase, and alpha ketoglutarate dehydrogenase

Question 47

How may times is H2O fed in this cycle?

Answer 47

3, before and after aconitase, and at fumarase

Question 48

How much ATP is made in the kreb cycle?

Answer 48

2atp/ acetyl coA oxidized but since 2 then it is 24 ATP ``` 3 NADH (9 ATP) 1 GTP (1 ATP) 1 FADH2 (2 ATP) ```

Question 49

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

Answer 49

werneke-korsakoff syndrome, and wet beri beri