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10 Cards in this Set
- Front
- Back
What is alkaptonuria?
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This is ochronosis, and is caused by the excess accumulation of homogentisic acid.
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What causes this?
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It results in a block in the metabolism of the phenylalanine tyrosine pathway, which is caused by a deficiency in homogentisic oxidase.
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What is the result of excess homogentisic acid?
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It causes the urine to turn dark upon standing after a period of time. It also causes a dark coloration, of the scleras, tendon and cartilage. A degenerative arthritis often follows.
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What is phenylketonuria?
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PKU also known as hyperphenylalaninemia, results from a deficiency of phenyalanine hydroxlase, an enzyme that oxidizes phenylalanine to tyrosine in the liver.
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Are infants normal at birth?
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Yes. But rising phenylalanine levels results in irreversible brain dadmge. The excess phenyacetic acid in the urine gives it a mousy odor.
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What is the result of a lackm of the enzyme fumarylacetoacetate hydrolase?
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Tyrosinemia. Chronic forms are associated with cirrhosis of the liver, kidney dysfunction, and a high risk of hepatocellular carcinoma.
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What is maple syrup urine disease?
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It is associated with an enzyme defect that causes the accumulation of branched chain alpha keto acid derivatives of isoleucine, leucine and valine.
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Albinisn refers to what?
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To a group of disorders characterized by an abnormality of the synthesis of melanin.
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Two forms of oculocutaneous albinism are classified by what?
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By the presence or absence of tyrosinase, which is the first enzyme in the conversion of tyrosine to melanin.
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Albvinos are at a much increased risk for the development of squamous cell carcinoma in sun exposed skin. T/F
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TRUE.
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