CITRIC ACID CYCLE Flashcards

1
Q

Also known as Krebs cycle or TCA Cycle; key metabolic pathway

A

Citric Acid Cycle

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2
Q

Conversion of glucose to pyruvate

A

Glycolysis

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3
Q

Converts pyruvate to acetyl-CoA

A

Pyruvate Dehydrogenase

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4
Q

Electron carrier in electron transport chain

A

Coenzyme Q

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5
Q

Generates ATP during oxidative phosphorylation

A

ATP Synthase

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6
Q

Electron carrier; reduced to NADH

A

NAD+

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7
Q

Electron carrier; reduced to FADH2

A

FAD

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8
Q

Site of citric acid cycle

A

Mitochondrial Matrix

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9
Q

Generates ATP during oxidative phosphorylation

A

Electron Transport Chain

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10
Q

ATP generation via electron transport chain

A

Oxidative Phosphorylation

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11
Q

Citric Acid Cycle enzymes

A

Citrate synthase, aconitase,
isocitrate dehydrogenase,
alpha-ketoglutarate dehydrogenase complex, succinate thiokinase, succinate dehydrogenase, Fumatase,
Malate dehydrogenase

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12
Q

Key regulatory enzyme in citric acid cycle

A

Alpha-Ketoglutarate Dehydrogenase

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12
Q

Converts succinyl-CoA to succinate

A

Succinyl-CoA Synthetase

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13
Q

Converts malate to oxaloacetate

A

Malate

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14
Q

Citric Acid Cycle regulation

A

Feedback inhibition by ATP, NADH, and Succinyl-CoA
Allosteric control by citrate synthase and isocitrate dehydrogenase
Substrate availability like acetyl-CoA and oxaloacetate

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14
Q

Replenish citric acid cycle intermediates

A

Anaplerotic reactions

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15
Q

Remove citric acid cycle intermediates

A

Cataplerotic reactions

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16
Q

Key regulatory enzyme

A

Citrate synthase

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17
Q

Converts isocitrate to alpha-ketoglutarate

A

Isocitrate dehydrogenase

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18
Q

Citric acid cycle intermediate and combined with Acetyl-CoA

A

Oxaloacetate

19
Q

Converts fumarate to malate

A

fumarase

20
Q

Exchanges ATP and ADP across mitochondrial membrane

A

ATP/ADP translocase

20
Q

Converts oxaloacetate to phosphoenolpyruvate

A

Phosphoenolpyruvate carboxykinase

21
Q

Citric Acid Cycle generates?

A

10 ATP
3 NADH
1 FADH2
2 CO2

22
Q

Inputs of Citric Acid Cycle

A

Acetyl-CoA, H20, O2

23
Q

ATP/ADP ratio

A

Regulates citric acid cycle activity

24
Q

Citric Acid Cycle connection to electron transport chain

A

Reducing equivalents; NADH and FADH2 generated in citric acid cycle fuel electron transport chain

25
Q

Citric Acid intermediates:

A
  1. Citrate
  2. Isocitrate
  3. Alpha-ketoglutarate
  4. Succinyl-CoA
  5. Succinate
  6. Fumarate
  7. Malate
  8. Oxaloacetate
26
Q

Occurs in advanced liver disease, leads to loss of consciousness, coma, and convulsion

A

Hyperammonemia

27
Q

Depletes the citric acid cycle intermediates and inhibits the oxidative decarboxylation of alpha-ketoglutarate

A

Ammonia

28
Q

Entry of carbon?

A

Anaplerosis

29
Q

Exit of carbon?

A

Cataplerosis

30
Q

found in some plants; inhibits aconitase causing the accumulation of citrate

A

Fluoroacetate

31
Q

Inhibits the reaction, causing substrate alpha-ketoglutarate to accumulate

A

Arsenite

32
Q

4 essential B vitamins in Citric Acid Cycle

A
  1. Riboflavin (FAD)
  2. Niacin (NAD+)
  3. Vitamin B1 (thiamin)
  4. Pantothenic acid
33
Q

cofactor for succinate dehydrogenase

A

FAD

34
Q

electron acceptor for isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, malate dehydrogenase

A

NAD+

35
Q

coenzyme for decarboxylation in the alpha-ketoglutarate dehydrogenase reaction

A

Thiamin (Vit. B1)

36
Q

esterified to carboxylic acids to form acetyl CoA and succinyl-CoA

A

Pantothenic acid

37
Q

Citric Acid Cycle is both

A

Oxidative & Synthetic process (amphibolic)

38
Q

Inhibit the reaction of the succinate to Fumarate

A

Malonate

39
Q

Citric Acid Cycle takes part in…

A

Gluconeogenesis
Transamination
Deamination

40
Q

An important substrate for gluconeogenesis, enters the cycle via oxidation to pyruvate and carboxylation to oxaloacetate

A

Lactate

41
Q

Important anaplerotic substances

A

Glutamine & Glutamate

42
Q

Major glucogenic product of rumen fermentation

A

Propionate

43
Q

Citric Acid takes part in …

A

Fatty Acid Synthesis

44
Q

Major substrate for long chain fatty acid synthesis

A

Acetyl-CoA

45
Q

the source of half the NADPH required for fatty acid synthesis

A

Malic enzyme