Q-Bank Biochemistry I

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*ol 2119

Which of the following choices best explain these dat?

Back 1

Normal enzyme control: Line Z;

Mutation producing INCREASED Km: Line Y;

Mutation DECREASING amount of functional enzyme: Line X

Front 2

*ol 083

Back 2

overcooked food

Front 3

m200028

Back 3

She inherited two X-chromosomes, both carrying a defective G6PD gene.

rest of explanation:

*She inherited two X- chromosomes, both carrying a defective G6PDH gene

*rest of explanation:
Choice B: If a normal woman inherits a single defective X-chromosome, the phenotype will NOT usually be expressed.

Choice C:
Inheriting an X-chromosome carrying a defected G6PD gene, which is translocated onto an autosome during meiosis, would be another mechanism that would account for expression of a disease phenotype by a heterozygous female in a recessive X-linked trait, but it would be VERY RARE.

Choice D:
Inheriting an X-chromosome carrying a defective G6PD gene may permit the phenotypic expression of a disease trait in a female carrying an X-linked recessive trait if there were incomplete inactivation of the chromosome. In such cases, the female would be expected to express the disease in an attenuated form.

Front 4

* ol309

Back 4

*2-3 MONTHS

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*OL 985

Back 5

The ratio of NADH to NAD+ is INCREASED

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*OL 2121

Back 6

3.00 mM

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*ol192

Back 7

2/3

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*m00066

Back 8

*Aminoacidopathy

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*ol 1661

Back 9

0%

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*ol1140

Back 10

*pyruvate kinase

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*m200057

Back 11

*Inactivation of tumor suppressor genes

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*ol 2038

Back 12

*methionine

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*1158

Back 13

*Acetoacetic acid

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*ol1956

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*CORRECT ANSWER:
LONG-CHAIN ACYL COA DEHYDROGENASE (LCAD) DEFICIENCY

Choice E:

Muscle glycogen phosphorylase deficiency, or McArdle disease, is also associated with muscle weakness and potential cardiomyopathy, but there is no associated hypoglycemia or hypoketosis. Muscle glycogen is NOT released as free glucose into the blood, and keton synthesis is a hepatic pathway assiciated with fatty acid oxidation in that tissue. A muscle biopsy of a patient with muscle glycogen phosphorylase deficiency would reveal glycogen deposits. There would be no increaswe in acyl carnitines.

Front 15

*ol 1673

Back 15

*Desmoglein

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*ol 1099

Back 16

*PHENYLEPHRINE

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*m200058

Back 17

*Removal of introns as lariat structures

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*ol 1652

Back 18

50%; 50%

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*ol 1647

Back 19

*A high proportion of the X chromosomes carrying the mutation are active.

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*ol 1650

Back 20

*2/3