Download biochem

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• A 26 year old woman has produced two children with Down
syndrome and she had two miscarriages. What is the best
explanation ?
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• A. First cousin has Down syndrome
• B. Her husband is 62 years old
• C. She carries a reciprocal translocation involving
chromosome 14 and 18
• D. She carries a robertsonian translocation involving
chromosomes 14 and 21
• E. She was exposed to multiple Xrays in childhood
• A man is suffering from Hemophilia A . If he
marries a normal genotype lady what percentage
of male children will have the disease?
• 0%
• 25%
• 50%
• 75%
• 100%
• A 16 year old boy is brought to his physician because of
inadequate development of his genitalia.Physical
examination shows hypogonadism and testicular
atrophy .He has a high pitched voice .Lab studies show
elevated FSH an LH but low levels of
testosterone.Breast buds have appeared in this boy .
Karyotyping will reveal which of the following ?
• 46 XY
• 47 XXY
• 47XYY
• 45 X
• TRISOMY 21
• A 56 year old male is hospitalized with abdominal pain
and hypotension. All of a sudden he begins to
hyperventilate .Lab investigations reveal metabolic
acidosis, increased anion gap and high lactate levels.
These findings are best explained by low activity of
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• Pyruvate kinase
• Lactate dehydrogenase
• Pyruvate carboxylase
• Phospho enol pyruvate carboxykinase
• Enolase
• Ingestion of ethanol and hypoglycemia have a
well-demonstrated relation. Ethanol decreases
the rate of formation of glucose by
gluconeogenesis. What is one of the mechanisms
behind this?
• A. Increased NADH
• B. Increased NADPH
• C. Increased FADH2
• D. Decreased Biotin
• E. Inactivation of pyruvate carboxylase
• How many ATP are produced after GLYCOLYSIS
with the 2,3BPG pathway in RBCS ?
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• A. 2
• B. 12.
• C. 32
• D. 38
• E. 0
• Atorvastatin, a cholesterol lowering medicine ,
would inhibit which of the following enzymes?
• HMG Co A synthase
• HMG CoA reductase
• HMG CoA lyase
• Acyl Co A dehydrogenase
• Squalene epoxidase
• Hartnups disease shows pellagra like symptoms
because of which of the following ?
• Decreased absorption of Phenylalanine from
intestine
• Decreased formation of Niacin from Tryptophan
• Dietary deficiency of Niacin
• Excessive catabolism of Tryptophan
• Deficiency of Tyrosinase
• Allpurinol is an inhibitior of which of the
following enzymes ?
• Xanthine oxidase
• Adenosine deaminase
• Purine nucleoside phosphorylase
• PRPP synthase
• HGPRTase
• What are the sources of the Nitrogen in the
urea molecule ?
• Ammonia and Aspartate
• Ammonia and Glutamine
• Ammonia and Uric acid
• Ammonia and glutamate
• Ammonia alone
• A 33 year old man from Kenya , living in US and
receiving antibiotic therapy for a UTI has a self limiting
eposiode of hemolysis and jaundice.The peripheral
blood smear reveals a nonspherocytic , normocytic
anaemia and Heinz bodies are seen in siome of his
RBCs.Which of the following is true ?
• Defect in homocysteine transmethylase and decreased
NADH
• Pyruvate kinase and decreased ATP
• Dihydrofolate resuctase and Vitamin B12
• Ferrochelatase and heme
• Glucose 6 P dehydrogenase and NADPH
• What is the most likely
pattern of inheritance of
the following disease?
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Autosomal dominant
Autosomal recessive
X-linked recessive
X-linked dominant
Mitochondrial inheritance