Brainscape's Knowledge GenomeTM

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


See full index

Biochemistry > Biochemisty - Nutrition > Flashcards

Biochemisty - Nutrition Flashcards

1
Q

Which Vitamins are fat soluble?

A

ADEK

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

Which vitamin is thiamine?

A

B1

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

Which vitamin is riboflavin?

A

B2

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

Which vitamin is niacin?

A

B3

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

Which vitamin is pantothenic acid?

A

B5

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

Which vitamin is biotin?

A

B7

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

Which vitamin is folate?

A

B9

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

Which vitamin is cobalamin?

A

B12

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

Which vitamin is ascorbic acid?

A

C

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

Which B vitamins do not wash out easily from the body?

A

B12 and folate (stored in liver).

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

What is the source of Vitamin A?

A

Liver and leafy greens.

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

What are the functions of Vitamin A?

A

1) Antioxidant 2) RETINAl = constituent of rhodopsin, visual pigment 3) essential for normal differentiation of epithelial cells into specialized tissue (panc cells, mucus secreting cells), 4) prevents squamous metaplasia

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

What are two diseases vitamin A is used in the treatment of?

A

measles and AML subtype M3

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

What does Vitamin A deficiency cause?

A

Night blindness (nyctalopia), dry scaly skin (xerosis cutis), corneal degeneration (keratomalacia), bitot spots (keratin accumulation) on conjunctiva, immunosuppresion

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

What does Vitamin A excess cause - acute toxicity?

A

Nausea, vomiting, vertigo, and blurred vision.

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

What does Vitamin A excess cause - chronic toxicity?

A

Alopecia, dry skin, hepatic toxicity and enlargement, arthralgias, and pseudotumor cerebri

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

What are the teratogenic manifestations of Vit A excess? How is this relevant clinically?

A

Cleft palate, cardiac abnormalities. Negative preg test and contraception method required before isoretinoin is prescribed for severe acne.

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

What is the function of thiamine?

A

Thiamine pyrophosphate (TPP) is a cofactor for several dehydogenase reactions: Alpha-ketoglutarate dehydrogenase (TCA cycle), Transketolase (HMP shunt), Pyruvate dehydrogenase (links glycolysis to TCA cycle). + Branched chain ketoacid dehydrogenase.

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

What is the mechanism of damage of thiamine deficiency?

A

Impaired glucose breakdown, ATP depletion worsened by glucose infusion. Highly aerobic tissues (brain, heart) affected first.

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

What is Wernicke-Korsakoff syndrome?

A

Caused by thiamine deficiency. Confusion, ophthalmoplegia, ataxia (classic triad), + confabulation, personality change, memory loss (PERMANENT). Damage to medial dorsal nucleus of thalamus, mammillary bodies.

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

What is dry beriberi?

A

*Ber1Ber1: Thiamine deficiency. Dry: polyneuritis, symmetrical muscle wasting.

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

What is wet beriberi?

A

*Ber1Ber1: Thiamine deficiency. High output cardiac failure (dilated cardiomyopathy), edema.

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

What is the function of B2?

A

RiboFlavin, necessary for flavins FAD and FMN, used as cofactors in redox, eg succinate dehydrogenase in TCA cycle.

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

What is the result of B2/riboflavin deficiency?

A

2Cs of B2: Cheilosis, Corneal vascularization.

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

What is the function of B3?

A

B3, niacin, is a constituent of NAD+/NADP+ used in redox reactions.

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

What does B3 comes from?

A

Tryptophan. Synthesis requires B2 and B6.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is B3 used to treat?

A

Niacin treats dysplipidemia by lowering VLDL and raising HDL.

28
Q

What does B3 deficiency cause?

A

3Ds of B3: Pellagra. Dermatitis (C3/C4 broad collar rash - casal necklace), Diarrhea, Dementia (&hallucinations). Also hyperpigmention of sun-exposed limbs.

29
Q

What can cause niacin deficiency?

A

Hartnup disease (lowers tryptophan absorption), malignant carcinoid syndrome (increases tryptophan metabolism), and isoniazid (decreases vitamin B6).

30
Q

What does B3 excess cause?

A

facial flushing (prostagladin induced! tx w/ aspirin), hyperglycemia, hyperuricemia.

31
Q

What does Vitamin B5 do?

A

Essential component of coenzyme A (CoA, a cofactor for acyl transfers) and fatty acid synthase.

32
Q

What does B5 deficiency cause?

A

Dermatitis, enteritis, alopecia, and adrenal insufficiency.

33
Q

What is the function of vitamin B6?

A

Pyridoxine is convereted to Pyridoxal Phosphate (PLP), cofactor used in transamination (AST and ALT), decarboxylation, glycogen phophorylase. Synthesis of cystathionine, HEME, niacin, histamine, and neurotransmitters serotonin, epi, norepi, dopa, GABA.

34
Q

What can cause B6 deficiency?

A

isoniazid and oral contraceptives

35
Q

What does B6 deficiency result in?

A

Convulsions, peripheral neuropathy, hyperirritability, sideroblastic anemias due to impaired hemoglobin synthesis and iron excess.

36
Q

What is the function of vitamin B7?

A

Cofactor for carboxylation enzymes (which add 1-carbon group). Pyruvate carboxylase, acetyl-Coa carboxylase, Propionyl-CoA carboxylase.

37
Q

What can cause B7 deficiency?

A

Rare. antibiotic use, excessive ingestion of egg whites (avidin).

38
Q

What is the result of B7 deficiency?

A

Dermatitis, alopecia, enteritis

39
Q

Where is B9 found and absorbed?

A

Folate from foliage - leafy greens. Absorbed in jejunum, small reserve pool in liver.

40
Q

What is the function of B9/folate?

A

Converted to THF (tetrahydrofolic acid), a coenzyme for 1-carbon transfer/methylation. Important for synthesis of nitrogenous bases in DNA/RNA.

41
Q

What can cause B9 deficiency?

A

Several drugs; methotrexate, phenytoin, sulfonamides, etc. Seen in alcoholism and pregnancy as well.

42
Q

What is the result of B9 deficiency?

A

Macrocytic, megaloblastic anemia. Hypersegmented polymorphonuclear cells, glossitis. Elevated homocystine. Normal methylmalonic acid and no neurologic sx (as opposed to B12).

43
Q

What is the source of B12?

A

Animal products. Synthesized only by microorganizsms. Very Large reserve pool (years) stored in liver.

44
Q

What is the function of B12?

A

Cofactor for homocysteine methyltransferase (transfers CH3 group as methylcobalamin, and methylmalonyl-CoA mutase).

45
Q

What are the causes of B12 deficiency?

A

Insufficient intake - strict, long-term veganism. Malaborsorpton/absence of terminal ileum. Lack of intrinsic factor (pernicious anemia, gastric bypass surgery) required for absorption. Anti-intrinsic factor antibodies diagnostic for pernicious anemia.

46
Q

What are the symptoms of B12 deficiency?

A

Macrocytic, megaloblastic anemia, hypersegmented PMNs, paresthesias/and subacute combined degenerated (degeneration of dorsal columns, lateral corticospinal tracts, and spinocerebellar tracts) due to abnormal myelin. Associated with increased serum homocysteine and methylmalonic acid levels. Prolonged deficiency can cause irreversible nerve damage.

47
Q

What is the source of Vitamin C?

A

Fruits and vegetables.

48
Q

What is the function of Vitamin C?

A

Antioxidant. Facilitates iron absorption by reducing it to Fe2+ state. Necessary for hydroxylation of proline and lysine in collagen synthesis. Necessary for dopamine B-hydroxylase, which converts dopamine to NE.

49
Q

What is the result of Vitamin C deficiency?

A

Scurvy! Collagen synthesis defect. Swollen gums, bruising, petechiae, perifollicular and subperiosteal hemorrhages, corkscrew hair. Weakened immune response.

50
Q

What is the result of Vitamin C excess?

A

Nausea, vomiting, diarrhea, fatigue, calcium oxalate nephrolithiasis. Can increase risk of iron toxicity in predisposed individuals (eg those with transfusions, hereditary hemochromatosis).

51
Q

What is the source of Vitamin D? What are the different forms?

A

D2, ergocalciferol from plants. D3 from milk and formed in the stratum basale of sun-exposed skin. 25-OH-D3 = storage form. 1-25-OHD3 (calitriol) is the active form (step 1 to calcidiol occurs in the liver, final step in the kidney).

52
Q

What is the function of Vitamin D?

A

To increase intestinal absorption of calcium and phosphate. To increase bone mineralization.

53
Q

What does deficiency of Vitamin D cause in children? In adults?

A

In children, Rickets: bone pain and deformity. Breast fed infants should receive oral vitamin D. Osteomalacia in adults (bone pain and muscle weakness), hypocalcemia tetany.

54
Q

What exacerbates Vitamin D deficiency?

A

low sun exposure, pigmented skin, prematurity.

55
Q

What is the result of Vitamin D excess?

A

Hypercalcemia, hypercalciuria, loss of appetite and stupor. Seen in granulomatous disease due to activation of vitaminD by epitheliod macs.

56
Q

What is the function of Vitamin E/tocopherol/tocotrienol?

A

Antioxidant (RBCs and membranes), can enhance anticoag effects of warfarin.

57
Q

What is the result of Vitamin E deficiency?

A

Hemolytic anemia, acanthocytosis, muscle weakness, posterior column and spinocerebellar tract deficiency.

58
Q

What can Vitamin E be confused with? What distinguishes them?

A

B12 deficiency due to neurological sx. But Vit E has no megaloblastic anemia, no hypersegmented neuts, and no increase in methylmalonic acid.

59
Q

What is the source of Vitamin K/phytomenadione/phylloquinone/phytonadione?

A

Synthesized by intestinal flora, found in greens.

60
Q

What are some causes of deficiency?

A

Neonates have sterile intestines, cannot synthesize; neonates given Vit K at birth. Can also occur after prolonged broad-spectrum antibiotics. Warfarin is an antagonist of epoxide reductase, which recycles vitamin K.

61
Q

What is the function of Vitamin K?

A

Cofactor for gamma carboxylation of glutamic acid residues on various proteins in the clotting cascade: 2,7,9,10, and proteins C and S.

62
Q

What are the symptoms of Vitamin K deficiency?

A

Neonatal hemorrhage/hemorrhage.

63
Q

What is the function of zinc?

A

Mineral essential for activity of 100+ enzymes. Important in the formation of “zinc fingers” - transcription factor motif.

64
Q

What does deficiency of zinc cause?

A

Delayed wound healing, hypogonadism, decreased in adult hair (axillary, facial, pubic), dysguesia, anosmia, acrodermatitis enteropathica: scaly, well-demarcated plaques in the intertriginous area. May predispose to alcoholic cirrhosis.

65
Q

What is kwashiorkor?

A

Protein deficiency resulting in Malnutition, Edema (due to decreased plasma oncotic pressure), Anemia, and Liver fatty change due to decreased apolipoprotein synthesis. Skin lesions. Clinical picture is a young child with swollen abdomen.

66
Q

What is marasmus?

A

Total calorie malnutrition resulting in tissue and muscle wasting, loss of subQ fat, and variable edema.

Biochemistry (11 decks)

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