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8 Cards in this Set
- Front
- Back
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What are porphyrins?
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Porphyrins are a group of organic ring molecules that serve as cofactors for a number of proteins and enzymes.
Porphyrins are "tetrapyrroles," many of which bind metal ions (such as iron) in the center. |
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What are the functions of porphyrins?
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-oxygen transport: hemo- and myoglobin
-electron transport, respiration -redox reactions: cytochrome p450 family, catalase: destruction of peroxide -other reactions: nitric oxide synthase |
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Which porphyrias are nonfluorescent?
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Porphyrias with Fe, Pb
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What is the first step in porphyrin biosynthesis?
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5-ALA synthase condenses succinyl-Co + glycine yield make ALA (δ-aminolevulinate)
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What does a deficiency of erythroid ALAS2 cause?
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XLSA, S-linked Sideroblastic Anemia
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What is the second step in porphyrin biosynthesis?
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Prophobilinogen synthase condenses 8 ALAs to form 4 porphobilinogens.
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What causes ALA dehyrdatase deficiency porphyria?
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A deficiency of ALAD.
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What is the rate controlling step in porphyrin biosynthesis?
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The formation of ALA (step 1).
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