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11 Cards in this Set
- Front
- Back
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which amino acid is deficient in phenylketonuria
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tyrosine - cannot metabolize from phenylalanine
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Defects in which 3 things can lead to hyperphenylalaninemia
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1. phneylalanine hydroxylase
2. synthesis of BH4 3. dihydropteridine reductase (generates BH4 from BH2) |
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deficiency in what leads to decreased synthesis of catecholamines and serotonin along with hyperphenylalaninemia
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BH4 or didydropteridine reductase
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3 classic characteristics of PKU
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1. Elevated phenylalanine results in musty odor
2. mental retardation 3. hypopigmentation |
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why do children with PKU have hypopigmentation
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lack of tyrosine to form melanin via tyrosinase
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do infants with PKU have abnormal blood levels of phenylalanine at birth
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No, usually 24-48 hours later because maternal liver cleared excess phenylalanine
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essential amino acid in patients with PKU
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tyrosine
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deficiency in branched-chain a-keto acid dehydrogenase
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maple syrup urine disease
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what accumulates in the blood causing toxic effects in patients with maple syrup urine disease
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a-keto acids
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which 3 enzymes require BH4 as a cofactor
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phenylalanine hydroxylase
tyrosine hydroxylase tryptophan hydroxylase |
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cofactors required for branched-chain a-ketoacid dehydrogenase
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thiamine
lipoamide CoA NAD |
