Bioch..9Q - maryam2009

[ArchivalUser]

An X-linked genetic disease affects a cation- transporting P-type ATPase ,resulting in accumulation of Copper in the intestinal epitelium because of failure to transport it normally into the blood.Infants with his disease have only 10% of normal blood copper levels. Arteriograms show elongation and tortuosity of major arteries.Bladder diverticula and subdural hematomas are also characteristic findings.These symptoms would most likely be caused by decreased activity of which of the following enzymes?

A.Cytchrome aa3
B.Lysyl oxidase
C.Prolyl hydroxylase
D.Gamma-Glutamyl carboxylase
E.Tyrosinase

[ArchivalUser]

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[ArchivalUser]

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[ArchivalUser]

Right

B..Menkes syndrome or Ehlers-Danlos syndrome type IX or kinky hair disease.
Lysyl oxidase requires copper and plays a direct role in collagen formation by catalysing the cross-linking of collagen fibrils.

Cytochrome aa3 does require copper ,but has no direct role in collagen formation.

Prolyl hydroxylase catalyses the hydroxyl action of proline on the nascent collagen fibers but does not requir copper.

Tyrosinase also is a copper -requiring enzyme ..plays role in melanin production.

Gamma -glutamyl carboxylation is a vit K dependent enzyme...catalizes the formation gamma carboxyglutamate required for chelation of calcium ion by the clotting factors.

[ArchivalUser]

Maryam, thank you so much for your biochem and genetic questions. THere re a good review before my test.

[ArchivalUser]

You are very welcome