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Flashcards in B vitamins Deck (34):
1

What is vitamin B1? What is the main molecule where vitamin B1 is found?

thiamine thiamine pyrophosphate

2

What is vitamin B2? What are the main two molecules that vitamin B2 is found?

riboflavin FAD and FMN

3

What rare inherited defect in amino acid transport can cause a niacin deficiency?

Hartnup disease

  • autosomal recessive defect in intestinal and renal transporters for neutral amino acids.
  • This causes tryptophan excretion in urine and leads to pellagra

4

Pt. with Diarrhea Dermatitis (classically in a "necklace" distribution around the neck) Dementia

Hartnup disease

5

What 2 vitamins help synthesize Niacin?

Tryptophan + B2 and B6

6

Pt is suspected of having thiamine deficiency. How can you confirm the Dx?

RBC transketolase activity will increase after the administration of thiamine

7

Confusion, ophthalmoplegia, ataxia (classic triad) +confabulation, personality change, memory loss (permanent). What nucleus is damaged?

Wernicke-Korsakoff syndrome Damage to medial dorsal nucleus of thalamus, mammillary bodies

8

Pt. suspected of having hypoglycemia. Treatment

give thiamine before dextrose to risk of precipitating Wernicke encephalopathy.

9

polyneuropathy, symmetrical muscle wasting.

Dry beriberi

10

Enzymes that require thymine (ATP)

α-ketoglutarate dehydrogenase (TCA cycle) Transketolase (HMP shunt) Pyruvate dehydrogenase (links glycolysis to TCA cycle) Branched-chain ketoacid dehydrogenase

11

High-output cardiac failure (dilated cardiomyopathy)

Wet Beri Beri

12

What type of cells are at risk of damage with B1 deficiency?

Highly aerobic cells are damaged first because they cannot generate ATP w/o thiamine

13

Dermatomes affected in B3 difficiency

C3/C4

14

The 2 C’sof B2 difficiencey

FAD and FMN (she has vitamin B2 deficiency manifesting as cheilosis and corneal vascularization)

15

A 42 yo presents w/photophobia, inflamed lips, and fissures at the sides of her mouth. Which TCA cycle cofactors are deficient?

cheilosis and corneal vascularization Biotin: needed for carboxylation reactions

16

What is Niacin used to treat? side effects?

Hyperlipidemia: lowers Hyperuricemia and hyperglycemia

17

How can carcinoid syndrom cause pelegra?

Carcinoid syndrome is a complication of carcinoid tumors (most commonly of the small bowel) in which serotonin is systemically elaborated in great excess. Tryptophan is compensatorily shunted to make serotonin, decreasing conversion to niacin. Therefore, niacin deficiency is a potential complication of carcinoid syndrome.

18

Gaba, Histamine and porphyrin/heme require what vitamin

B6

19

Creatine, Urea, and Nitric oxide require which a.a.

Arginine

20

only non water soluble B vitamin

B12 cobalomin in liver

21

Which vitamin is needed for decarboxylation reactions and is also a cofactor for glycogen phosphorylase?

B6

22

What parkinson drug therapy is decreased by vit b6 therapy

L-Dopa therapy vitamin B6 can convert L-DOPA to dopamine peripherally (as opposed to in the CNS), rendering treatment less efficacious.

23

What complex of the electron transport chain is FMN and FAD part of.

Component of NADH dehydrogenase, aka complex I of the electron transport chain component of succinate dehydrogenase of the TCA cycle, aka complex II of the electron transport chain

24

What vitamin is prevented from being absorbed by a certain protein in eggs?

Avidin... binds biotin

25

Two etiologies that cause a vitamin deficiency and results in the following : Dermatitis Alopecia Enteritis Adrenal insufficiency

Biotin B7 antibiotic use or excessive consumption of raw egg whites

26

Two etiologies that cause a vitamin diffieciecy and results in the following? Transamination Decarboxylation Glycogen phosphorylase

B6

27

what 4 neurotransmitter synthesis reactions require B6

Glutamate → GABA Tryptophan → Serotonin DOPA → Dopamine (dopamine can then go on to form norepinephrine and epinephrine) Histidine → Histamine

28

Vitamin needed for Co-enzyme A

B5

29

Medications that can induce Vitamin B6 deficiency

include oral contraceptives and isoniazid.

30

B6 is a precursor for what cofactor

PLP

31

A 32 yo woman begins taking isoniazid after a TB Dx. Later, she develops numbness and tingling in her extremities. Dx?

B6 deficiency

32

A man w/vitamin deficiency complains of fatigue, convulsions, hyperirritability, and peripheral neuropathy. Why is he experiencing fatigue?

He has sideroblastic anemia caused by vitamin B6 deficiency Microcytic

33

Pt w/anemia has ringed sideroblasts on bone marrow biopsy. Which vitamin deficiency could cause this?

B6

34

Which vitamin is required for the synthesis of an intermediate in the formation of cysteine?

B6--> cystathionine Can lead to homocysteinuria