FA Amboss vit B2 ir vit K

Question 1

B2 name?

Answer 1

riboflavin

Question 2

B2 substance class?

Answer 2

flavins

Question 3

Inactive precursor (provitamin): of vit b2?

Answer 3

none

Question 4

what are 2 active forms of vit b2?

Answer 4

Active forms: flavin mononucleotide (FMN),
flavin adenine dinucleotide (FAD)

Question 5

sources of vit b2?

Answer 5

Sources: meat, fish, eggs, milk, green vegetables, yeast[

Question 6

vit b2 transport in blood?

Answer 6

Transport in blood: via albumin and immunoglobulins

Question 7

resorption of vit b2?

Answer 7

Resorption: flavoproteins are cleaved into riboflavin in the intestine

Question 8

FAD and FMN are cofactors for enzymes that are involved in what reactions?

Answer 8

in redox reactions (chemical reactions in which electrons are transferred from one substance to another).

Question 9

what are 2 redox reactions?

Answer 9

Succinate dehydrogenase (TCA cycle)

FAD is part of glutathione reductase (GR) in erythrocytes: NADPH binds to GR → reduction of FAD to FADH- → FADH- breaks disulfide bond in GSSG → GSR can be reduced

Question 10

FAD is part of …… in erythrocytes.

Answer 10

glutathione reductase (GR)

Question 11

FAD is part of glutathione reductase (GR) in …

Answer 11

erythrocytes

Question 12

vit b2 def causes?

Answer 12

Malnutrition

Restricted diet (e.g., vegan, lactose-free)

↑ Demand: pregnancy, lactation

Question 13

manifestation of vit b2 def?

Answer 13

Corneal vascularization

Cheilitis, glossitis, stomatitis, pharyngitis

Normocytic normochromic anemia

Seborrheic dermatitis

Question 14

2 ways to diagnose vit b2 def?

Answer 14

Erythrocyte glutathione reductase assay: identifies subtle deficiencies

Erythrocyte glutathione reductase activity coefficient: the activity coefficient (AC) of glutathione reductase is measured in the presence and absence of FAD

Question 15

name of vit K?

Answer 15

phytomenadione

Question 16

Vitamin K1 names?

Vitamin K1 (phytomenadione, phytonadione, or phylloquinone)

Answer 16

.

Question 17

Vitamin K2 name?

Vitamin K2 (menaquinone)

Answer 17

.

Question 18

vit K substance class?

Answer 18

Substance class: naphthoquinones

Question 19

vit K inactive precursors (provitamins)?

Answer 19

none

Question 20

Active form of vit K?

Answer 20

Active form: vitamin K hydroquinone

Question 21

Activation of vit K occurs via what enzyme?

Answer 21

Epoxide reductase.

Question 22

Mutations in the ……. gene impair the reduction of vitamin K epoxide.

Answer 22

VKORC1 (Vitamin K epOxide Reductase Complex subunit 1) gene

Question 23

VKORC1 abbreviation?

Answer 23

(Vitamin K epOxide Reductase Complex subunit 1)

Question 24

Mutations in the VKORC1 gene leads to what deficiency of coagulation?

Answer 24

deficiencies in vitamin K-dependent clotting factors.

Question 25

sources of vit K?

Answer 25

Leafy green vegetables (vitamin K1)

Eggs, dairy, and meat (vitamin K2)

Synthesized in small amounts by intestinal bacteria

Question 26

transport of vit K?

Answer 26

Transport: via lipoproteins; no specific protein

Question 27

Storage of vit K?

Answer 27

Liver

Question 28

Excretion of vit K?

Answer 28

bile and urine

Question 29

vit K is cofactor for?

Answer 29

Cofactor for γ-carboxylation

Question 30

γ-carboxylation of what structure?

Answer 30

Cofactor for γ-carboxylation of glutamate residues on vitamin-K-dependent proteins involved in:

Question 31

Cofactor for γ-carboxylation of glutamate residues on vitamin-K-dependent proteins involved in: what 2 process?

Answer 31

coagulation and bone formation

Question 32

γ-carboxylation. Coagulation?

Answer 32

Coagulation: maturation of factors II (prothrombin), VII, IX, and X, protein C, protein S

Question 33

γ-carboxylation. Bone formation?

Answer 33

Bone formation: osteocalcin (bone Gla protein), matrix Gla protein

Question 34

5 causes of vit K deficiency?

Answer 34

Liver failure (e.g., cirrhosis)

Fat malabsorption

Prolonged broad-spectrum antibiotic therapy

Vitamin K antagonists (e.g., warfarin)

Neonatal deficiency

Question 35

why neonates have vit k deficiency?

Answer 35

The neonatal intestine is sterile (no flora to synthesize vitamin K).

Vitamin K does not cross the placenta.

Breast milk does not contain vitamin K.

The neonatal liver is incapable of synthesizing the active form of vitamin K.

Question 36

clinical manifestation of vit K def? cia tipo buvo neonatal, bet bus ciuju visiems

Answer 36

Hemorrhage (e.g., petechiae, ecchymoses)

Vitamin K deficiency bleeding (VKDB):
↑ PT and aPTT, normal bleeding time

Question 37

what is postnatal prophylaxis of vit K def?

Answer 37

Postnatal prophylaxis: vitamin K injection at birth

Question 38

what parameters are prolonged in vit K def?

Answer 38

↑ PT and aPTT, normal bleeding time

Question 39

cause of vit K toxicity?

Answer 39

Oversupplementation

Question 40

manifestation of vit K toxicity?

Answer 40

Hemolytic anemia
Hyperbilirubinemia
Jaundice
Kernicterus in infants

Question 41

2 therapeutic use of vit K?

Answer 41

Postnatal vitamin K injection to prevent VKDB

Coagulopathy: disorders of the extrinsic pathway of coagulation.

Question 42

vit B2 deficiency?

…………………….

Cheilitis, glossitis, stomatitis, pharyngitis

Normocytic normochromic anemia

Seborrheic dermatitis

Answer 42

Corneal vascularization

Question 43

vit B2 deficiency?

Corneal vascularization

…………………..

Normocytic normochromic anemia

Seborrheic dermatitis

Answer 43

Cheilitis, glossitis, stomatitis, pharyngitis

Question 44

vit B2 deficiency?

Corneal vascularization

Cheilitis, glossitis, stomatitis, pharyngitis

…………………

Seborrheic dermatitis

Answer 44

Normocytic normochromic anemia

Question 45

vit B2 deficiency?

Corneal vascularization

Cheilitis, glossitis, stomatitis, pharyngitis

Normocytic normochromic anemia

……………

Answer 45

Seborrheic dermatitis