bmsc 230 module 6 citric acid cycle

0.0(0)
studied byStudied by 0 people
learnLearn
examPractice Test
spaced repetitionSpaced Repetition
heart puzzleMatch
flashcardsFlashcards
Card Sorting

1/69

encourage image

There's no tags or description

Looks like no tags are added yet.

Study Analytics
Name
Mastery
Learn
Test
Matching
Spaced

No study sessions yet.

70 Terms

1
New cards

What are other common names for the citric acid cycle?

TCA cycle and Krebs cycle

2
New cards

What is the citric acid cycle?

completes the breakdown of glucose

3
New cards

Where does the TCA cycle occur?

mitochondrial matrix

4
New cards

What does acetyl CoA combine with in the citric acid cycle?

Oxaloacetate to make a 6 Carbon intermediate

5
New cards

Net reaction of TCA cycle?

acetyl CoA + 3NAD+ + FAD + GDP + Pi + H20 --> 3NADH + FADH2 + GTP + CoA + 2CO2

6
New cards

What are the products of TCA?

3 NADH
1 FADH2
1 GTP
2 CO2

7
New cards

What is oxidative phosphorylation?

Uses energy released by the electron transport chain to power ATP synthesis.

8
New cards

Where are the enzymes for the TCA cycle?

all are floating in mitochondrial matrix except one is bound to the inner mitochondrial matrix

9
New cards

Step 1 of TCA cycle? Cofactors?

Oxaloacetate --> Citrate

Cofactors: Acetyl CoA --> + CoA

10
New cards

What enzyme catalyzes step 1 of TCA cycle?

Citrate Synthase

11
New cards

What kind of reaction is step 1 of TCA cycle?

Condensation

12
New cards

Step 2 of TCA cycle? Cofactors?

Citrate --> Isocitrate

Cofactors: H2O --> H20

13
New cards

What enzyme catalyzes step 2 of TCA cycle? what happens?

aconitase. removes water molecule and reattch at different carbon

14
New cards

What kind of reaction is step 2 of TCA cycle?

Dehydration, rehydration

15
New cards

Step 3 of TCA cycle? Cofactors?

isocitrate --> alpha-ketoglutarate

Cofactors: NAD+ --> NADH + CO2

16
New cards

What enzyme catalyzes step 3 of TCA cycle?

isocitrate dehydrogenase

17
New cards

What kind of reaction is step 3 of TCA cycle?

oxidative and decarboxylation

18
New cards

Step 4 of TCA cycle? Cofactors?

alpha-ketoglutarate --> succinyl-coA

Cofactors: NAD+ + CoA --> NADH + CO2

19
New cards

What enzyme catalyzes step 4 of TCA cycle?

alpha-ketoglutarate dehydrogenase complex

20
New cards

What kind of reaction is step 4 of TCA cycle?

Oxidative decarboxylation

21
New cards

Step 5 of TCA cycle? Cofactors?

succinyl-CoA --> succinate

Cofactors: ADP + Pi --> ATP + CoA

22
New cards

What enzyme catalyzes Step 5 of TCA cycle?

succinyl-CoA synthetase

23
New cards

What kind of reaction is step 5 of TCA cycle?

substrate level phosphorylation

24
New cards

Step 6 of TCA cycle? Cofactors?

succinate --> fumarate

Cofactors: FAD --> FADH2

25
New cards

What enzyme catalyzes step 6 of TCA cycle?

Succinate dehydrogenase

26
New cards

What kind of reaction is step 6 of TCA cycle?

Dehydrogenation

27
New cards

Step 7 of TCA cycle? Cofactors?

fumarate --> malate

Cofactors: H20

28
New cards

what enzyme catalyzes step 7 of TCA cycle?

fumarase

29
New cards

what kind of reaction is step 7 of TCA cycle?

hydration

30
New cards

Step 8 of TCA cycle? Cofactors

malate --> oxaloacetate

Cofactors: NAD+ --> NADH

31
New cards

What enzyme catalyzes step 8 of TCA cycle?

Malate Dehydrogenase

32
New cards

What kind of reaction is step 8 of TCA cycle?

Dehydrogenation

33
New cards

One turn of the TCA cycle

-two carbons enter
(acetyl CoA)
-2 carbons leave via 2 CO2 from oxaloacetate
-3 NADH
-1 FADHS
-1 GTP = ATP
-Oxaloacetate regenerated

34
New cards

what does the oxidation of glucose yield?

2 pyruvate

35
New cards

How many ATP does NADH yield?

2.5 ATP

36
New cards

How many ATP does FADH2 yield?

1.5 ATP

37
New cards

What regulates the TCA cycle?

  1. phosphorylation of pyruvate dehydrogenase

  2. TCA cycle enzymes. the two irreversible reactions

38
New cards

what reactions are not reversible in TCA cycle?

-isocitrate dehydrogenase
-alpha-ketoglutarate dehydrogenase

39
New cards

activators and inhibitors of isocitrate dehydrogenase

Activators: ADP

Inhibitors: ATP and NADH

40
New cards

Inhibitors of alpha-ketoglutarate dehydrogenase

ADP, Succinyl CoA, NADH

41
New cards

What can Citrate be used for other than the TCA cycle?

Fatty acids and sterols

42
New cards

What can alpha-ketoglutarate be used for other than the TCA cycle?

Glutamate --> other amino acids --> Purines

43
New cards

What can Succinyl CoA be used for other than the TCA cycle?

Porphyrins, heme, chlorophyll

44
New cards

What can Oxaloacetate be used for other than the TCA cycle?

Amino acids

45
New cards

What are anaplerotic reactions?

Reactions that replenish citric acid cycle intermediates

46
New cards

Anaplerotic carboxylase reaction in TCA cycle

Pyruvate carboxylase (idk)

Pyruvate undergoing carboxylation to make oxalaoacetate

47
New cards

What does fluoroacetate do to the TCA cycle?

inhibits aconitase and the formation of isocitrate

48
New cards

Why is the inhibition of aconitase detrimental?

blocks the TCA cycle
accumulation of Citrate and energy depletion
seizures

49
New cards

What is the glyoxylate cycle?

It is similar to the citric acid cycle but bypasses the two decarboxylation steps, allowing the synthesis of carbohydrates from fats

50
New cards

When is the glyoxylate cycle highly active in oil seed plants?

During germination because it helps synthesize energy before they can photosynthesize

51
New cards

Where does the glyoxylate cycle occur?

glyoxysomes

52
New cards

Glyoxylate cycles main function?

produce succinate to be converted to oxaloacetate and then into glucose

53
New cards

Step 1 of glyoxylate cycle? Cofactors?

oxaloacetate --> Citrate

Cofactors: Acetyl CoA + H20 --> CoA

54
New cards

What enzyme catalyzes step 1 of glyoxylate cycle?

Citrate Synthase

55
New cards

Step 2 of glyoxylate cycle? Cofactors?

Citrate --> Isocitrate

Cofactors: H20 --> H20

56
New cards

What enzyme catalyzes step 2 of glyoxylate cycle? What happens?

Aconitase. Removes water molecule and reattach at different carbon

57
New cards

What kind of reaction is step 2 of the glyoxylate cycle?

Dehydration, Rehydration

58
New cards

Step 3 of glyoxylate cycle?

Isocitrate --> Succinate + Glyoxylate

59
New cards

What happens to the succinate produced in the glyoxylate cycle?

Goes into the mitochondria and enters the citric acid cycle

60
New cards

What enzyme catalyzes step 3 of the glyoxylate cycle?

Isocitrate lyase

61
New cards

What does a lyase enzyme do?

One molecules is broken down into two

62
New cards

Step 4 of glyoxylate cycle? Cofactors?

Glyoxylate --> Malate

Cofactors: Acetyl CoA + H20 --> CoA

63
New cards

What enzyme catalyzes step 4 of the glyoxylate cycle? what happens?

Malate Synthase. Glyoxylate condenses with acetyl CoA

64
New cards

Step 5 of the glyoxylate cycle? Cofactors?

Malate --> Oxaloacetate

Cofactors: NAD+ --> NADH + H+

65
New cards

What enzyme catalyzes step 5 of the glyoxylate cycle? what happens?

Malate dehydrogenase. Malate is oxidized

66
New cards

What reactions are bypasses in the glyoxylate cycle?

Isocitrate dehydrogenase and the alpha-ketoglutarate dehydrogenase reactions

67
New cards

What does one cycle of the glyoxylate cycle use and produce?

2 Acetyl CoA and produces 1 succinate

68
New cards

What 4 pathways are involved in conversion of fat to glucose in plants?

  1. Fatty Acid Oxidation to generate Acetyl CoA (glyoxysomes)
  2. Glyoxylate cycle (Glyoxysome)
  3. TCA cycle (mitochondria)
  4. Gluconeogenesis (Cytoplasm)
69
New cards

Glyoxylate cycle and Citric Acid cycle overall reactions?

(Lipid Body) TAG--> FA --(Glyoxysome)--> Acetyl CoA--> Succinate-- (Mtio) --> Malate --(Cytoplasm)--> Oxaloacetate --> Glucose

70
New cards

What are the two different enzymes in the glyoxylate cycle compared to the TCA cycle?

Isocitrate lyase and Malate synthase