TCA

Question 0

What is congenital lactic acidosis?

Answer 0

Mutation in pyruvate dehydrogenase leading to accumulation of lactate

Question 1

Pyruvate is made into Acetyl CoA by?

Answer 1

Pyruvate dehydrogenase

Question 2

How is pyuvate dehydrogenase regulated?

Answer 2

Positive: ADP
Negative: NADH and Acetyl CoA
Kinase and Phosphotase phosphorylate and dephos respectively

Question 3

T or F: Pyruvate to Acetyl CoA is irreversible

Answer 3

T

Question 4

Phosphorylated pyruvate dehydrogenase is active or inactive?

Answer 4

Inactive

Question 5

Pyruvate to Acetyl CoA produces?

Answer 5

CO2 and NADH+H

Question 6

Pyruvate to Acetyl CoA is called what type of reaction?

Answer 6

Oxidative decarboxylation

Question 7

T or F: Pyruvate dehydrogenase phosphorylation is regulated by cAMP pathways

Answer 7

F

Question 8

Name the 5 cofactors required for Pyruvate dehydrogenase

Answer 8

CoA, TPP (Thiamine pyrophosphate), Lipoic acid, FAD, and NAD+

Question 9

Describe the structure of pyruvate dehydrogenase

Answer 9

2 active sites, 2 regulatory sites, and 5 cofactors (very complex)

Question 10

TCA: Acetyl CoA feeds in and?

Answer 10

Citrate synthase combines oxaloacetate and acetyl CoA into Citrate losing CoASH and consuming water in an oxidative decarboxylation step

Question 11

TCA: Citrate is…

Answer 11

Made into isocitrate by acontiase

Question 12

TCA: Citrate to Isocitrate is a reversible reaction. T or F?

Answer 12

T

Question 13

TCA: Isocitrate is…

Answer 13

Made to Alpha-Ketoglutarate via isocitrate dehydrogenase. Produces a NADH +H and CO2

Question 14

TCA: Which step in the cycle is most highly regulated?

Answer 14

Isocitrate to Alpha-ketoglutarate

Question 15

TCA: Alpha-ketoglutarate is…

Answer 15

Oxidatively decarboxylated by Alpha-ketoglutarate dehydrogenase to made succinyl CoA consuming CoASH and producing NADH +H and CO2

Question 16

T or F: Alpha-ketoglutarate dehydrogenase is regulated by the same 5 cofactors as pyruvate dehydrogenase

Answer 16

T

Question 17

T or F: GTP and ATP are equivalent

Answer 17

T

Question 18

TCA: Succinyl CoA is…

Answer 18

Made into succinate by succinate thiokinase producing GTP and CoASH

Question 19

What step in TCA involves substrate level phosphorylation?

Answer 19

Succinyl CoA to Succinate

Question 20

Succinate thiokinase is also called?

Answer 20

Succinyl CoA synthetase

Question 21

T or F: The TCA cycle has a net gain of carbon

Answer 21

F

Question 22

TCA: Succinate is…

Answer 22

Succinate dehydrogenase makes Fumarate and produces FADH2

Question 23

What is another name for succinate dehydrogenase?

Answer 23

Complex II

Question 24

TCA: Fumarate is...

Answer 24

Converted to Malate by consuming H20 via Fumarase

Question 25

TCA: Malate is...

Answer 25

Converted to Oxaloacetate by malate dehydrogenase to produce NADH +H

Question 26

Which steps of TCA made NADH+H?

Answer 26

Isocitrate to Alpha-ketoglutarate (isocitrate dehydrogenase); Alpha-ketogluarate to Succinyl CoA (Alpha-ketoglutarate dehydrogenase); Malate to Oxaloacetate (malate dehydrogenase).

Question 27

FADH2 is produced in what step of TCA?

Answer 27

Succinate to Fumarate via Succinate dehydrogenase

Question 28

TCA: Water is consumed at what steps?

Answer 28

Fumarate to Malate (fumarase); Oxaloacetate and Acetyl CoA to Citrate via citrate synthase

Question 29

TCA: CO2 is produced at what steps?

Answer 29

Isocitrate to Alpha-ketoglutarate (isocitrate dehydrogenase); Alpha -ketoglutarate to Succinyl CoA (Alpha-ketoglutarate dehydrogenase)

Question 30

TCA: Which step produces substrate level phosphorylation?

Answer 30

Sucicnyl CoA to Succinate (Succinate thiokinase)

Question 31

How many revolutions of TCA occur per glucose?

Answer 31

2

Question 32

Name the 5 sources for acetyl CoA?

Answer 32

Acetate, Pyruvate (glucose), Fatty acid, ketone bodies, amino acids

Question 33

What is the net reaction for TCA?

Answer 33

Acetyl CoA + 3NAD+ + FAD + GDP + P +2 H20 = 2 CO2 +CoASH + 3NADH +3 H+ + FAD2H + GTP

Question 34

What does anapleurotic mean?

Answer 34

Reactions that fill up (replenish the TCA intermediates)

Question 35

Oxaloacetate is replenished by?

Answer 35

AA and Pyruvate plus CO2

Question 36

Citrate is siphoned to?

Answer 36

Fatty acids and cholesterol

Question 37

Alpha-ketoglutarate is replenished by?

Answer 37

AA

Question 38

Succinyl CoA is siphoned and replenished by?

Answer 38

Siphoned to make porphyrins | Replenished by isoleucine, methionine, valine, and odd chain fatty acids

Question 39

Fumarate is replenished by?

Answer 39

Asparate, phenylalanine, tyrosine

Question 40

Malate is siphoned to make?

Answer 40

Glucose

Question 41

Citrate synthestase is inhibited by?

Answer 41

Citrate

Question 42

Isocitrate dehydrogenase is regulated by?

Answer 42

Positive: ADP and Ca+2 Negative: NADH and ATP

Question 43

Alpha-ketoglutarate dehydrogenase is regulated by?

Answer 43

Negative: NADH and Succinyl CoA Positive: Ca+2

Question 44

What are the three irreversible steps of TCA?

Answer 44

Isocitrate to alpha-ketoglutarate, Acetyl-CoA feed in, Alpha-ketoglutarate to Succinyl CoA

Question 45

Which is the only enzyme for TCA not free in the mitochondrial matrix?

Answer 45

Succinate dehydrogenase