Lecture 46 Flashcards Preview

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Flashcards in Lecture 46 Deck (8)
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1
Q

PKU results from a mutation in ______ hydroxylase, resulting in accumulation of _____, which would otherwise be converted to _____, a precursor for melanin OR a deficiency in _______ reductase, the enzyme responsible for converting BH2 back to BH4.

A

PKU results from a mutation in PHENYALANINE hydroxylase, resulting in accumulation of PHENYLALANINE, which would otherwise be converted to TYROSINE, a precursor for melanin OR a deficiency in DIHYDROPTERIDINE reductase

2
Q

A mutation in the Dihydropteridine reductase would present with a more sever phenotype, showing deficiency in catecholamine and _____ synthesis.

A

Catecholamine and SEROTONIN synthesis.

3
Q

Maple Syrup Urine Disease is characterized by a deficiency in the enzyme ______ dehydrogenase (BCKD), which decarboxylates branch chain alpha-keto acids. Urine has a maple syrup odor.

A

Deficiency in the enzyme BRANCHED CHAIN ALPHA-KETO ACID DEHYDROGENASE.

4
Q

Albinism results primarily from an autosomal recessive deficiency in the enzyme ______, which requires copper. This enzyme is needed to convert _____ to DOPA quinone and eventually to melanin.

A

Deficiency in TYROSINASE, which requires copper. This enzyme is needed to convert TYROSINE to DOPA quinone and eventually to melanin.

5
Q

A defect in Cystathionine beta-synthase or deficiency in vitamins ____or ____ can cause _______. Symptoms include lens dislocation and skeletal abnormalities. ______ and ______ levels are elevated as a result of this disease.

A

Defect in Cystathionine beta-synthase or deficiency in vitamins B6 or B12 can cause HOMOCYSTINURIA. METHIONINE and HOMOCYSTINE levels are elevated.

6
Q

Higher levels of homocystine in the blood are positively correlated with increased risk for _______ mortality.

A

CARDIOVASCULAR

7
Q

______ can be detected by almost black urine which arises from a buildup of homogentisic acid (an intermediate in the degradation pathway of _____.) It can lead to joint pain (arthritis) and collagen issues.

A

ALKAPTONURIA can be detected by almost black urine which arises from a buildup of homogentisic acid (an intermediate in the degradation pathway of TYROSINE.)

8
Q

Urea comes off from _______ when it is converted to ______ via the enzyme ______.

A

Urea comes off from L-arginine when it is converted to ORNITHINE via the enzyme ARGINASE