Glycolysis, TCA cycle, pyruvate, electron transport chain Flashcards Preview

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Flashcards in Glycolysis, TCA cycle, pyruvate, electron transport chain Deck (76)
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Glycolysis site

Cytoplasm

1

Glycolysis site and all steps (not the enzymes)

Cytoplasm
Glucose --> Glucose-6-P --> Fructose-6-P -->
Fructose-1,6-BP --> Gltceraldehyde-3-P --> 1,3 biphosphoglycerate --> 3-phosphoglycerate --> 2-phosphoglycerate --> phosphoenolpyruvate (PEP)
--> Pyruvate

2

Hexokinase regulation

Glucose -6-P -

3

Glycolysis steps that require ATP

Glucose to 6-P- glucose (hexokinase/glucokinase)
Fructose 6-P to fructose -1,6- BP (phosphofrouktokinase

4

Glucokinase regulation

Fructose-6-P -

5

Glucokinase vs hexokinase about location

Glucokinase in liver and β cells of pancreas
Hexokinase in all other tissues

6

Glycolysis stpes that produce ATP

1,3-Biphosphoglycerate to 3-phosphoglycerate (phosphoglycerate kinase)
Phosphoenolpyruvate to pyruvate (pyruvate kinase)

7

Glycolysis stpes that produce ATP

1,3-Biphosphoglycerate to 3-phosphoglycerate (phosphoglycerate kinase)
Phosphoenolpyruvate to pyruvate (pyruvate kinase)

8

Fructose-6-P to fructose-2,6-BP

Phosphofructokinase -2 (activate in fed state)

9

Fructose -2,6-biphosphate enzymes (and active when)

1. Fructose bisphosphate-2 --> active in fasting
2. Phosphofructokinase-2 --> active in fed

10

Fructose-2,6-BP to fructose-6-P

Fructose bisphosphatase-2 (active in fasting state)

11

Fructose-2,6-bisphosphate/fasting state

Glucagon --> increased cAMP --> increased protein kinase A --> increased fructose bisphosphatase-2, decreased phosphofuctokinase-2,less glycolysis, more gluconeogenesis

12

Fructose bisphosphate-2 vs Phosphofructokinase-2 according to action and regulation

Are the same bifunctional enzyme whose function is reversed by phosphorylation

13

Fructose-2,6-bisphosphate/fed state

Insulin --> decreased cAMP --> decreased protein kinase A --> decreased fructose bisphosphatase-2, increased phosphofuctokinase-2, more glycolysis, less gluconeogenesis

14

Pyruvate dehydrogenase complex site
What does it link?

MITOCHONDRIAL ENZYME complex linking glycolysis and TCA cycle

15

Pyruvate dehydrogenase complex regulation

Active in fed state, not in fasting

16

Pyruvate dehydrogenase complex reaction

Pyruvate + NAD + CoA --> acetyl CoA + CO2 + NADH

17

Pyruvate dehydrogenase complex contain how many enzymes

3

18

Pyruvate dehydrogenase complex cofactors

1. Pyrophosphate (B1, TPP)
2. FAD (riboflavin B2)
3. NAD (B3, niacin)
4. CoA (B5, pantothenate)
5. Lipoic acid

20

Pyruvate dehydrogenase complex activated in by

1. increased NAD+/NADH ratio
2. increased ADP
3. Increased Ca2+

21

The Pyruvate dehydrogenase complex is similar to

a-ketoglutarate dehydrogenase complex (same cofactors, similar substrate and action

21

Lipoic acid inhibitor

Arsenic

22


a-ketoglutarate dehydrogenase complex converts

a-ketoglutarate --> succinyl-CoA (TCA)

23

Arsenic acid inhibits lipoic acids. Findings

1. Vomiting
2. Rice water stools
3. Garlic breath

24

Arsenic action

Inhibit glycolysis
Inhibit lipoic acid (dehydrogenase complex)

25

Pyruvate dehydrogenase complex deficiency causes

A buildup of pyruvate that gets shunted to lactate (via LDH) and alanine (via ALT)

26

Glycolysis pathway (mediators)

Glucose glucose-6-P fructose-6-P fructose-1-6-BP glyceraldehyde-3-P 1,3-biphosphoglycerate
2-phosphoglycerate phosphoenolpyruvate --> pyruvate

28

Pyruvate dehydrogenase complex deficiency treatments

Increased intake of ketogenic nutrients (high fat content or increased lysine and leucine

28

Pyruvate dehydrogenase complex deficiency findings

1. Neurologic defects
2. Lactic acidosis
3. Serum alanine starting in infancy

29

Ketogenic amino acid vs glucogenic aminoacid

A ketogenic amino acid is an amino acid that can be degraded directly into acetyl CoA through ketogenesis. This is in contrast to the glucogenic amino acids, which are converted into glucose.

31

The only purely ketogenic amino acids

Lysine
Leucine

32

Pyruvate metabolism deferent pathways (+enzymes and site)

1. Alamine (ALT-B6)-cytoplasm (Cahill cycle)
2. Oxaloacetate (PC + CO2 + ATP)-mitochondria
3. Acetyl-CoA (PDH + NAD)-mitochondria
4. Lactate (LDH +NADH+H)-cytoplasm

32

Pyruvate to alanine (reaction, site, enzyme, function)

Pyruvate alanine (ALT+B6) cytoplasm
Function: alanine carries amino groups to the liver from muscle (Cahill cycle)

33

Pyruvate pathways function

1. Alanine: carries amino groups to liver from muscle (Cahill cycle)
2. Oxaloacetate: can replenish TCA cycle or be used in gluconeogenesis
3. Acetyl-Coa: transition from glycolysis to TCA
4. Lactic acid: end of anaerobic glycolysis (major pathway of RBC, leukocytes, kidney medulla, lens, testes, cornea) (Cori cycle)

34

Alanine cycle also called

Cahill cycle

35

Aminotransferase cofactor

B6

36

LDH

Lactic acid dehydrogenase

37

Pyruvate to Lactate (reaction, site, enzyme, function)

Pyruvate+NADH+H --> lactate+NAD (LDH +B3) cytoplasm
Function: end of anaerobic glycolysis

38

Pyruvate to lactate is major pathway for which tissues

RBCs, leukocytes, kidney medulla, lens, testes, cornea

39

Pyruvate to oxaloacetate (reaction, site, enzyme, function)

Pyruvate + CO2 + ATP-->oxaloacetate (pyruvate carboxylase + biotin) Mitochondria
Function: oxaloacetate can replenish TCA cycle or cycle or be used in gluconeogenesis

40

Pyruvate to acetyl-Coa (reaction, site, enzyme, function)

Pyruvate+NAD --> acetyl-CoA + CO2 + NADH+H (pyruvate dehydrogenase, B1, B2, B3, B5, lipoic acid) Mitochondria
Function: transition from glycolysis to the TCA cycle

42

TCA cycle produces
site?

3 NADH, 1 FADH2, 2 Co2, 1 GTPper acetyl coa (2 x everything per glucose) --> 10 ATP / acetyl coa
site mitochondria

43

TCA cycle - every step

- Acetyl-CoA (2C) + Oxaloacetate (4C) --> Citrate (6C) (Citrate synthase)
- Citrate --> cis-Aconitate --> Isocitrate
- Isocitrate --> a-KG (5C) + CO2 + NADH (isocitrate dehydrogenase)
- a-KG (5C) --> Succinyl-Coa (4C) + CO2 + NADH (a-KG dehydrogenase
- Succinyl-Coa (4C) --> Succinate + CoA + GTP
- Succinate --> Fumarate + FDH2
- Fumarate --> Malate --> Oxaloacetate + NADH

44

A-ketogluterate dehydrogenase cofactors

Same as the pyruvate dehydrogenase
B1, B2, B3, B5, lipoic acid

44

Citrine synthase regulator

ATP-

45

pyruvate dehydrogenase regulator

-ATP
-acetyl CoA
-NADH

46

Isocitrate dehydrogenase regulator

ATP-
NADH-
ADP+

48

A-ketoglorate dehydrogenase regulators

Succinyl CoA -
NADH-
ATP-

48

NADH production reaction of TCA

Isocitrate--> a ketoglutorate + CO2 + NADH
a ketoglutorate--> succinyl coa + CO2 + NADH
Malate--> oxaloacetete + NADH

49

Irreversible enzymes of TCA cycle

1. Pyruvate dehydrogenase
2. Isocitrate dehydrogenase
3. a ketoglutorate dehydrogenase
4. Citrate synthase

50

FAD2 production reaction of TCA

Succinate --> fumareta + FAD2

51

GTP production reaction of TCA

Succinate CoA --> succinyl + CoA + GTP

52

NADH Electrons from glycolysis enter mitochondria via

1. Malate-aspartate shuttle
2. Glycerol phosphate shuttle

53

FADH2 electrons are transferred to

Complex II (at a lower energy level than NADH

54

NADH electrons are transferred to

Complex I

55

Complex II name

Succinate dehydrogenase

56

Proton gradient purpose

Is coupled to oxidative phosphorylation, it drives the production of ATP

57

The passage of electrons to intermembrane matrix through....results in the formation of a...

Complex I, Complex III, and Complex IV
Proton gradient

58

Which complex of electron transport chain produce water

Complex IV
1/2O2 + 2H H2O

59

Which complex of electron transport chain produce ATP

Complex V

60

H+ go to mitochondrial matrix through

Complex V

61

Molecule between complex II and III

CoQ

62

Molecule between complex III and IV

Cytochrome c

63

Complex I inhibitor

Rotenone

64

Complex III inhibitor

Antimycin A

65

Complex IV inhibitor

Cyanide
CO

66

Complex V inhibitor

Oligomiycin

67

Electron transport inhibitors

Rotenone, cyanide, antimycin A, CO
Directly inhibit electron transport, causing a decreased proton gradient and block of ATP synthesis

68

ATP produce via ATP synthase in oxidative phosphorylation

2,5 ATP per NADH
1,5 ATP per FADH2

69

ATP synthase inhibitors

Oligomycin
Directly inhibit mitochondrial ATP synthase , causing an increased proton gradient. No ATP is produce because electron transport stop

70

Electron transport chain-uncoupling agent mechanism of action

Imcreased permeability of membrane, causing a decreased proton gradient and increased O2 consumption. ATP synthesis stops, but electron transport continues. Produces heat

72

Electron transport chain-uncoupling agents

2,4-Dinitrophenol (used illicitly for weight loss)
Aspirin (fevers often occur after aspirin overdose)
Thermogenin in brown fat

73

phosphofructokinase - 1 in glycolisis - mechanism of action and regulation

Fructose-6-P --> Fructose - 1,6-BP
+: AMP, fructose-2,6-BP
-: ATP, Citrate

74

Pyruvate kinase regulation

1. Fructose 1,6 BP +
2. ATP -
3. Alanine -

75

Inhibitors of every step of electron transport chain and oxidative phosphorylation

Complex I --> rotenone
Complex III --> Antimycin A
Complex IV --> Cyanide, CO
Complex V --> oligomycin
Uncoupling agents --> Dinitrophenol, aspirin, thermogenein

76

2,4-Dinitrophenol - clinical use

illicitly for weight loss