Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Nutrition 3330 > 2. Thiamin, riboflavin, niacin > Flashcards

2. Thiamin, riboflavin, niacin Flashcards

1
Q

General functions of B vitamins (4)

A
  1. micronutrient metabolism
  2. energy production ATP
  3. energy release
  4. carbon metabolism - transfer of single carbon units
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Coenzymes

A

required for the activity of enzymes

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

enzymes

A

at as catalysts, drive many reactions and pathways

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

relation of B vitamins and coenzymes?

A

part of the “structure” of coenzymes

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

T/F

B vits work together?

A

True

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

Vitamins are involved in Intermediary Metabolism of …? (5)

A
  1. Carbs
  2. Proteins
  3. Fats
  4. ATP Generation
  5. Nucleic Acids/Fatty Acids/Steriods
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Carb metabolism pathways vitamins are involved in?

A

glycolysis and gluconeogenesis

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

Protein metabolism pathways vitamins are involved in?

A

Protein synthesis and amino acid oxidation

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

Fat metabolism pathways vitamins are involved in?

A

FA synthesis and Beta oxidation

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

ATP generation metabolism pathways vitamins are involved in?

A

Respiratory chain and oxidative phosphorylation

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

Nucleic Acids/Fatty Acids/Steriods metabolism pathways vitamins are involved in?

A

pentose phosphate pathways

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

What is added to thiamine to synthesize its coenzyme form?

A

Phosphates

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

What is thiamines coenzyme form?

A

Thiamine pyrophosphate (TPP)

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

Thiamine’s main metabolic role

A
  • facilitates energy release from foods

- central role in carb metabolism

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

Reactions thiamine is involved in?

2 types
multiple enzymes

A
  1. Oxidative decarboxylations:
    - pyruvate dehydrogenase
    - alpha-ketoglutarate dehydrogenase
  2. Transketolase Reactions:
    - transketolase (requires magnesium)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Thiamines short form?

A

B1

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

thiamine requires what other vitamin to perform transketolase reactions?

A

Magnesium

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

TCA cycle full name?

A

Citric Acid Cycle

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

Thiamine deficiency?

A

Beri-Beri

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

Translation of beri-beri?

A

i can’t i cant

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

Symptoms of beri beri?

A

*** anorexia + weight loss
neurological symptoms
paralysis
cardiovasc + resp

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

What deficiency causes beri-beri?

A

thiamine

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

T/F

-disease can’t be reversed

A

False:

Thiamine reverses disease rapidly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Why is beri beri rare?

A

Thiamine is fortified in Canadian flour since 1949

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is thiamine fortified in?

A

Canadian Flour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

3 types of beri-beri?

A
  1. Wet (edema)
  2. Dry (no edema)
  3. Infantile
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Symptoms Wet beri-beri (edema)

A

cardio-resp

  • heart swelling
  • pulmonary congestion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Symptoms dry beri-beri (no edema)

A
  • central nervous system impairment
  • (alcohol - Wernicke-Korsakoff Syndrome)
  • confusion, memory loss, confabulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What does edema mean?

A

Swelling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What does “confabulation” mean?

A

memory disturbance

-fabricated, distorted or misinterpreted memories about oneself or the world, without the conscious intention to deceive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Cause of Infantile beri-beri?

Symptoms?

A

breast fed infants of deficient mothers

  • vomiting, diarrhea, convulsions
  • aphonia
  • sudden death can occur
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what is “aphonia” ?

A

inability to produce voice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Thiamine deficiency has been identified in what major disease? (Why?)

A

Diabetes

Consider role of thiamine in glucose metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

3 benefits of thiamine? (particularly in diabetes patients)

A

improved glucose metabolism, imflammatory status and vascular function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

2 Health claims in Europe regarding thiamine?

A
  • Normal carb and energy-yeilding metabolism

- Maintenance of normal neurological function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Why is riboflavin called B2

A

2nd B vit discovered

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

3 forms of riboflavin?

A
  1. Riboflavin
  2. Flavin Mononucleotide FMN (added Phosphate)
  3. Flavin Adenine Dinucleotide FAD (added phosphate, ribose and adenine)

*FMN and FAD are the coenzyme forms

38
Q

Riboflavin essential for what conversion?

A

conversion of B6 to is co-enzyme forms

39
Q

Riboflavins coenzyme forms?

A

FMN - Flavin Mononucleotide

FAD - Flavin Adenine Dinucleotide

40
Q

Riboflavin’s metabolic roles?

A

accept/donate hydrogen (on OH 3)
- FAD

Flavin-dependent enzymes (flavoproteins)
- Electron Transport Chain (Respiratory Chain)

41
Q

Riboflavin involvement in TCA cycle?

Relation to the electron transport chain?

A

TCA Cycle
- FAD accept 2H+ from Succinate –> Fumarate

Electron transport chain
- FADH2 involved with coenzyme Q

42
Q

Riboflavin involvement in TCA cycle?

Relation to the electron transport chain?

A 
TCA Cycle (OH 1 and 4)
- FAD accept 2H+ from Succinate --> Fumarate

Electron transport chain
- FADH2 involved with coenzyme Q

43
Q

Photolabile

A

susceptible to change with light

44
Q

Riboflavin food sources?

Fortified in?

A

Milk products, liver, meat

fortified flour in Canada

45
Q

What processing destroys thiamine and riboflavin?

A

Milling of wheat

46
Q

True/False

Riboflavin deficiency can be fatal?

A

False

Deficiency is non specific and never fatal

47
Q

Symptoms of riboflavin deficiency

A

lesion symptoms

  • cheilosis
  • megenta tongue
  • angular stomatitis (mouth)
  • soborrheic dermatitis (skin)
48
Q

**What other vitamin could riboflavin def affect?

A

Iron

Why??

49
Q

Iron status can be interfered with from what vitamin deficiency

A

riboflavin

50
Q

How does riboflavin deficiency affect iron? (2)

A
  1. Impairs mobilization of iron from its storage protein (ferritin)
  2. Impairs iron absorption
51
Q

Studies of women show correcting a marginal riboflavin deficiency improves _____ status

(other than but related to iron)

A

hemoglobin status

52
Q

B3 name

A

Niacin

53
Q

Niacins other name

A

B3

54
Q

2 chemical structures of niacin?

where are they found

A 
Nicotinic Acid (drug form)
Nicotinimide (major blood circulating form)
55
Q

2 Co-enzyme forms of niacin?

A

NAD(H) - Nicotinamide adenine dinucleotide

NADP(H)

56
Q

Where does the action occur for the coenzymes of Niacin?

A

at the Nitrogen

57
Q

Niacin can be synthesized from what amino acid?

A

tryptphan

58
Q

What ratio is niacin synthesized from tryptophan?

A

60mg tryptophan = 1mg of niacin

59
Q

What macronutrient must be considered when calculating niacin intake?

A

Protein

- niacin can be synthesized from the amino acid tryptophan

60
Q

meaning of Niacin Equivalent?

A

units used to express niacin content of food. It represents preformed niacin plus tryptophan equivalents (60 mg tryptophan = 1 mg niacin).

61
Q

Kynurinine Pathway

A

a metabolic pathway leading to the production of nicotinamide adenine dinucleotide (NAD+) from the degradation of the essential amino acid tryptophan

62
Q

What is the key intermediate in kynurenine pathway

A

kynurenine

63
Q

What vit(s) are needed in the Kynurinine Pathway?

A

riboflavin + B6

64
Q

Does Kynurinine Pathway produce enough niacin?

A

No, niacin still essential in the diet

  • completely replaces need in rodents dogs and pigs
65
Q

Major steps and vitamins involved in the Kynurinine Pathway

A

Tryptophan –> Kynurine –> NAD/NADP

riboflavin and B6 needed for Kynurine –> NAD/NADP

66
Q

Metabolic role of niacin (3)

A
  • macronutrient metabolism
  • transfers hydrogen during metabolic reactions
  • oxidation/reduction reactions
67
Q

How many enzyme is niacin involved with?

A

Atleast 200

68
Q

Where is niacin used in the TCA cycle?

A

all NAD+ –> NADH+H+

  1. ** Pyruvate –> Acetyl CoA

2/3. Isocitric Acid –> alpha ketoglutaric acid –> succinyl-Coa

  1. Malic Acid –> Oxaloacetic Acid
    (final step, re-enters TCA cycle)
69
Q

Niacin in the Electron Transport Chain?

A

10 NADH enter the start from 1 molecule of glucose

Decarboxylation reactions:
2 NADH glucose–> pyretic acid (Glycolysis)
2 NADH pyruvate –> acetyl CoA
6 NADH (TCA cycle)

70
Q

Niacin in Glycolysis/Gluconeogenesis

A

Glycolysis:
Glyceraldehyde-3-phosphate –> 1,3 Biphosphoglycerate

NAD+ –> NADH+H+

Gluconeogenesis:
reverse

71
Q

Niacin in Pentose Phosphate Pathway

A

Glucose-6-phosphate –> Ribose-5-phosphate

2x NADP –> NADPH + H+

72
Q

2 purposes of the pentose phosphate pathway?

A
  1. generate “NADPH” used for synthesis of “FA and steroids”

2. generate “ribose” for synthesis of “nucleic acids”

73
Q

Oxidation means hydrogen ______ ?

A

Acceptor

ex. NAD(P) –> NAD(P)H

74
Q

Reduction means hydrogen ______?

A

Donor

ex. NAD(P)H –> NAD(P)

75
Q

Niacin “oxidation” is used for the metabolism of? (4)

A

NAD(P) –> NAD(P)H

Pyruvate, TCA intermediates, glycolysis intermediates, pentose phosphate pathway

76
Q

Niacin “reduction” is used for?

A

NAD(P)H –> NAD(P)

Reductive biosynthesis of fatty acids and steroids

77
Q

Where is NADPH generated?

A

Pentose Phosphate Pathway

78
Q

Pellagra is italian for?

A

rough skin

79
Q

What disease is associated with Niacin deficiency

A

pellagra

80
Q

Pellagra is associated with a deficiency of what vitamin

A

Niacin (B3)

81
Q

Symptoms of pellagra

A

4 D’s

  • diarrhea
  • dermatitis
  • dementia
  • death

*case study OH 7

82
Q

Hartnup’s Disease

Improved with?

A
  • Autosomal recessive disorder
  • Develop pellagra (niacin deficiency) due to defect in absorption process for Tryptophan

improved with nicotinamide treatment

83
Q

Causes of pellagra symptoms in absence of dietary niacin deficiency? (2)

A
  • Isoniaizid; prolonged treatment (drug competes with B6, needed in the Kururenine pathway)
  • Hartnup’s Disease (autosomal recessive disorder, defect in tryptophan absorption)
84
Q

Problem with niacin in corn?

How to fix it?

A

Niacin bond and unavailable
- also low in tryptophan

Alkali treatment (ex. lime water) breaks bond

85
Q

Niacin requirement is expressed as?

A

Niacin Equivalent (NE)

86
Q

Niacin (Nicotinic Acid) typically used to treat what disease? Why?

A

CVD

Cholesterol lowering agent

87
Q

Why is Nicotinic Acid unique among lipid-lowering drugs (such as statins)

A

Reduce LDL cholesterol (typical)

Increase HDL cholesterol
Decrease Lipoprotein (a)
88
Q

Benefits of niacin (nicotinic acid) with cardiovascular disease?

A
  • lowers LDL and lipoprotein (a)
  • increase HDL
  • prevents progression of atherosclerotic lesions in coronary arteries

often used in combination with other drugs

89
Q

Did increase HDL studies (from niacin) show decrease in heart attacks, strokes or need for angioplasty?

A

no

LDL lowering showed greater heart stability but no correlation to HDL levels

90
Q

Niacin Flush

A

common side effect to niacin treatment

  • abdominal pain, rash, liver toxicity
  • rapidly absorbed GI tract
91
Q

How to reduce niacin flush symptoms?

A

take with meals
avoid hot liquids + alcohol
work dose up gradually
– Extended-release niacin (Niaspan)

92
Q

Large scale niacin flush problem?

A

Uncle Ben’s Rice

- excessive Niacin when served in food service establishments

Nutrition 3330 (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions