TCA cycle Flashcards

1
Q

location of TCA cycle?

A

Mitochondira

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Most cells contain how many mitochondria?

A

500-2,000

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Primary role of Mitochondria is?

A

ATP production via aerobic respiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a common product in the catabolism of carbohydrates (glycolysis), amino acids and fatty acids (B-oxidation)?

A

Acetyl- CoA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Catabolism?

A

Breakdown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Anabolism?

A

Synthesis of molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How is TCA a amphibolic pathway?

A

because it involves both catabolism and anabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Acetyl Coa has how many carbons?

A

2 carbons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Oxaloacetate has how many carbons?

A

4 carbons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Acetyl- CoA to Citrate. What is released?

A

CoA is released

Citrate has 6 carbons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Isocitrate to alpha ketoglutarate

A

NADH produced
CO2 released
Alpha-keto = 5 carbons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Alpha- ketoglutarate to succinyl-CoA ?

A

CoA added
CO2 released
NADH produced
Succinyl-CoA = 4 carbons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Succinyl-CoA to Succinate

A

GTP and CoA released.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Succinate to Fumurate

A

FADH2 released

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Fumurate to malate

A

H20 added

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Malate to Oxaloacetate

A

NADH produced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

energy rich components are added into the TCA cycle where?

A

Acetyl-CoA is added in the beginning of TCA and succinly-coA.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Oxidative Phosphorylation happens in the?

A

Inner mitochondrial matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Metabolic Fates of Pyruvate.

Pyruvate is reduced to what and with what enzyme?

A

Reduced to Lactate

via lactate dehydrogenase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Metabolic Fates of Pyruvate
When Pyruvate is oxidative decarboxylation it becomes?
With what enzyme?

A

Acetyl-CoA

3 carbon to 2 carbon via pyruvate dehydrogenase complex.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Metabolic Fates of Pyruvate.
When Pyruvate is carboxylized it becomes?
with what enzyme?

A

Pyruvate carboxylase

and it becomes oxalacetate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Pyruvate is transamination

what does it become via what enzyme?

A

becomes alanine

via alanine aminotransferase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

A porin in the mitochondria?

A

a special carrier for pyruvate involving a symport that utilizes the H+ gradient from outside to inside the mitochondrion.

24
Q

High selective transporters are where in the mitochondria?

A

inner!

25
Q

Pyruvate dehydrogenase complex (PDC) is a complex

of what three enzyme activities that transform pyruvate into acetyl-CoA by a process called pyruvate decarboxylation?

A
  • pyruvate dehydrogenase
  • dihydrolipoyl tranacetylase with its lipoic acid prosthetic group
  • dihydrolipyl dehydrogenase
26
Q

Pyruvate dehydrogenase is inhibited when one or more of the three following ratios are increased:

A

ATP/ADP
NADH/NAD+
Acetyl-CoA/CoA

27
Q

Acetyle-Coa , NADH and Pyruvate are ?

A

allosteric inhibitors

  • they upregulate PDH kinase which renders the PDH complex inactive
  • Acetyl-Coa can also Allosterically directly inhibit the PDH complex
28
Q

Phopshorlaytion of PDH kinase

A

Inactive PDH Complex

29
Q

dephosphorylation of PDH kinase

A

Active PDH complex

30
Q

PDH phosphatase upregulation

A

active PDH complex

31
Q

Insulin and cofactors

A

upregulate PDH phosphatase
which
activates PDH complex

32
Q

What makes Acetyl- CoA?

A

Fatty Acids
Pyruvate
Amino Acids

33
Q

Acetyl-Coa can produce?

A

Ketone bodies
Tricarboxylic acid
sterols
fatty acids

34
Q

Acetyl- Coa to Citrate?

enzyme

A

citrate synthesis

35
Q

isocitrate to alpha keto

A

RLE is : isocitrate dehydrogenase

36
Q

alpha keto to succuniyl coa

A

alpha-keto dehydrogenase

37
Q

succiynl coa to succinate

A

succinyl coa synthetase

38
Q

succinate to fummurate

A

succinate dehydrogenase

39
Q

malate to oxaloacetate

A

malate dehydrogenase

40
Q

Energy producing steps and also sites of regulation

A

Citrate synthase
Isoitrate Dehydrogenase
Alpha keto dehydrogenase

41
Q

TCA cycle inhibition for Citrate Synthase

A

Inhibition: ATP
NADH
Citrate
Succinyl-CoA

Activation: ADP

42
Q

TCA cycle activation

A

by ADP and CA

43
Q

TCA cycle needs both?

A

acetyl-coa and oxolacetate

44
Q

Pyruvate to Oxoalacetate needs what cofactor to fxn with enzyme?

A

biotin with pyruvate decoarboxylase

45
Q

TCA releases both Carbons from Acetyl-Coa as?

A

Co2

46
Q

TCA cycle produces?

A

3 NADH
1 FADH2
1 GTP

47
Q

Isocitrate dehydrogenase is what in TCA?

A

its the rate limiting step and most important and controlled by ATP and NADH

48
Q

TCA cycle serves as a

A

metabolic traffic circle that receives carbon skeletons from amino acids and fatty acids and donates carbon skeletons to amino acids and porphyrins

49
Q

Genetic mutations affecting the TCA cycle and accumulation of TCA cycle intermediates (???) or TCA cycle substrates (???) appear to be particularly toxic to neurons and brain development (encephalopathies).

A

Genetic mutations affecting the TCA cycle and accumulation of TCA cycle intermediates (succinate, fumarate) or TCA cycle substrates (pyruvate) appear to be particularly toxic to neurons and brain development (encephalopathies).

50
Q

Pyruvate dehydrogenase deficiency, leading to what?

Children with this disease frequently exhibit severe (blank) defects; resulting in death in many cases.

Dietary management may include?

A

leading to chronic lactic acidosis

severe neurological defects

ketogenic diet

51
Q

Fumarase deficiency?

Urine contains?

A

Rare autosomal recessive disease with severe neurological impairment.

Urine contains:
abnormal amounts of fumarate
and elevated levels of succinate
and other TCA cycle intermediates.

52
Q

TCA cycle dysfunctions can lead to

A

encephalopathies and certain types of cancer.

53
Q

TCA cycle inhibition for Isocitrate Dehydrogenase

A

ATP

54
Q

TCA cycle inhibition for Alpha keto dehydrogenase

A

NADH, Succinyl-Coa

55
Q

TCA cycle Activation for alpha keto dehydrogenase

A

Ca 2+

56
Q

TCA cycle Activation for Isocitrate dehydrogenase

A

Ca 2+, ADP

57
Q

TCA cycle activation for citrate synthase

A

ADP