Transcript biochem
• • A 26 year old woman has produced two children with Down syndrome and she had two miscarriages. What is the best explanation ? • • 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 • • 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 ? • • 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? • • • • • Autosomal dominant Autosomal recessive X-linked recessive X-linked dominant Mitochondrial inheritance