Porphyrins

Question 0

Chemical structure of heme (# of pyrrole rings and the valence of iron)

Answer 0

Tetrapyrole ring (4 rings) with alpha/beta chains and iron with a 2+ valence

Question 1

Two anatomical sites in the body where porphyrins are synthesized

Answer 1

Marrow or long bones and liver

Question 2

Enzyme deficiency for the most common porphyria

-porphyria cutanea tarda

Answer 2

uroporphyrinogen decarboxylase

Question 3

Enzyme deficiency/ inhibition in lead toxicity

Answer 3

Gamma-Aminolevulinic acid dehydratase

Question 4

Enzyme deficiency in Acute Intermittent Porphyria

Answer 4

Porphobilinogen deaminase

Question 5

Enzyme deficiency resulting in Congenital Erythropoietic Porphyria

Answer 5

Uroporphyringogen III cosynthase

Question 6

Enzyme deficiency resulting in Erythropoietic Protoporphyria; the enzyme necessary for the incorporation of iron in protoporphyrin IX

Answer 6

Ferrochelatase

Question 7

these are unstable, colorless, and non-fluorescent

Answer 7

porphyrinogens (reduced porphyrins)

Question 8

these are stable, colored (dark red or purple), and fluorescent (excite at 420nm; emission at 620nm)

Answer 8

Porphyrins

Question 9

reagent used in the porphyrin screening test

Answer 9

Erlich’s Reagent

Question 10

Best method for quantitative porphyrin assays

Answer 10

Liquid Chromatography (LC) or LC/MS

Question 11

Three most common porphyrias

Answer 11

Acute intermittent porphyria, porphyria cutanea tarda, and erythropoietic porphyria/protoporphyria

Question 12

one typical symptom of acute intermittent porphyria

Answer 12

acute abdominal pain

Question 13

Exacerbating factors of acute intermittent porphyria

Answer 13

drugs/alcohol, fasting/dieting, oral contraceptives

Question 14

porphyrin that is increased in acute intermittent porphyria

Answer 14

increased porphobilinogen (PBG)

Question 15

what happens as a urine sample from a patient with acute intermittent porphyria is left at room temp for at least 2 hours

Answer 15

urine gets darker red/port wine color as it sets

Question 16

FOur typical symptoms of porphyria cutanea tarda

Answer 16

fragile skin, blisters, scarring, hyperpigmentation

Question 17

Porphyrin that is increased in porphyria cutanea tarda

Answer 17

Urinary uroporphyrinogen III

Question 18

Two symptoms of erythropoietic protoporphyria

Answer 18

painful skin with skin swelling (congenital or aquired)

Question 19

Four physical characteristics and typical color of urine of a ptient with congenital erythropoietic porphyria

Answer 19

Extreme photosensitivity, reddish/brown teeth staining, mental retardation, abnormal growth patterns; urine is pink/red

Question 20

Two enzymes in the heme biosynthetic pathway that are inhibited in lead poisoning

Answer 20

ALA dehydrase and ferrochelatase

Question 21

What is typically analyzed in the lab to difinitively diagnose lead poisoning?

Answer 21

Increased urinary 5-ALA and coproporphyrin, Increased RBC zinc protoporphyrin, and increased lead in whole blood