Description : Orotic aciduria type II reflects the deficiency of the enzyme: (A) Orotate phosphoribosyl transferase (B) Orotidylate decarboxylase (C) Dihydroorotase (D) Dihydroorotate dehydrogenase
Last Answer : Answer : B
Description : Orotic aciduria type I reflects the deficiency of enzymes: (A) Orotate phosphoribosyl transferase and orotidylate decarboxylase (B) Dihydroorotate dehydrogenase (C) Dihydroorotase (D) Carbamoyl phosphate synthetase
Last Answer : Answer : A
Description : An alternate substrate for orotate phosphoribosyl transferase is (A) Allopurinol (B) Xanthine (C) Hypoxanthine (D) Adenine
Last Answer : Answer : D
Description : Methotrexate blocks the synthesis of thymidine monophosphate by inhibiting the activity of the enzyme: (A) Dihydrofolate reductase (B) Orotate phosphoribosyl transferase (C) Ribonucleotide reductase (D) Dihydroorotase
Description : In inherited deficiency of hypoxanthine guanine phosphoribosyl transferase (A) De novo synthesis of purine nucleotides is decreased (B) Salvage of purines is decreased (C) Salvage of purines is increased (D) Synthesis of uric acid is decreased
Description : Transfer of the carbamoyl moiety of carbamoyl phosphate to ornithine is catalysed by a liver mitochondrial enzyme: (A) Carbamoyl phosphate synthetase (B) Ornithine transcarbamoylase (C) N-acetyl glutamate synthetase (D) N-acetyl glutamate hydrolase
Description : All of the following occur in orotic aciduria except (A) Increased synthesis of pyrimidine nucleotides (B) Increased excretion of orotic acid in urine (C) Decreased synthesis of cytidine triphosphate (D) Retardation of growth
Description : Congenital deficiency of ornithine transcarbamoylase causes (A) Hyperammonaemia type I (B) Hyperammonaemia type II (C) Hyperornithinaemia (D) Citrullinaemia
Last Answer : Answer : C
Description : Hyperargininemia, a defect in urea synthesis develops due to deficiency of the enzyme: (A) Ornithine transcarbamoylase (B) Argininosuccinase (C) Arginase (D) Argininosuccinate synthetase ENZYMES 157
Description : Folic acid deficiency can be diagnosed by increased urinary excretion of (A) Methylmalonate (B) Figlu (C) Cystathionine (D) Creatinine
Description : All the following are true about phenylketonuria except (A) Deficiency of phenylalanine hydroxylase (B) Mental retardation (C) Increased urinary excretion of p-hydroxyphenyl pyruvic acid (D) Decrease serotonin formation
Description : Which of the following enzyme defects is associated with a characteristic body odour? 1) Phenylalanine aminotransferase 2) Galactose0-phosphate-uridyltransferase 3) Ornithine transcarbamylase deficiency 4) Fumaryl acetoacetase 5) Branched chain ketoacid decarboxylase
Last Answer : Answers-5 The following inborn errors of amino acid metabolism are associated with abnormal odours: Glutaric acidaemia type II (sweaty feet), hawkinsinuria (swimming pool), isovaleric acidaemia (sweaty feet), ... The general rule is that if a child smells peculiar he requires a metabolic work-up.
Description : All the enzymes required for de novo synthesis of pyrimidine nucleotides are cytosolic except (A) Carbamoyl phosphate synthetase (B) Aspartate transcarbamoylase (C) Dihydro-orotase (D) Dihydro-orotate dehydrogenase
Description : All the following statements about primary gout are true except (A) Its inheritance is X-linked recessive (B) It can be due to increased activity of PRPP synthetase (C) It can be ... activity of hypoxanthine guanine phosphoribosyl transferase (D) De novo synthesis of purines is increased in it
Description : An enzyme of pyrimidine nucleotide biosynthesis sensitive to allosteric regulation is (A) Aspartate transcarbamoylase (B) Dihydroorotase (C) Dihydroorotate dehydrogenase (D) Orotidylic acid decarboxylase
Description : An inborn error, maple syrup urine disease is due to deficiency of the enzyme: (A) Isovaleryl-CoAhydrogenase (B) Phenylalnine hydroxylase (C) Adenosyl transferase (D) α-Ketoacid decarboxylase
Description : Increased serum ornithine carabamoyl transferase activity is diagnostic of (A) Myocardial infarction (B) Hemolytic jaundice (C) Bone disease (D) Acute viral hepatitis
Description : Hyperammonaemia type I results from congenital absence of (A) Glutamate dehydrogenase (B) Carbamoyl phosphate synthetase (C) Ornithine transcarbamoylase (D) None of these
Description : Enzyme deficient in Hyperammonemia type II is (A) Glutamine synthetase (B) Glutaminase (C) Ornithine transcarbamoylase (D) Carbamoylphosphate synthetase
Description : An enzyme which is excreted in urine is (A) Lactase dehydrogenase (B) Amylase (C) Ornithine transcarbamoylase (D) None of these
Description : Control of urea cycle involves the enzyme: (A) Carbamoyl phosphate synthetase (B) Ornithine transcarbamoylase (C) Argininosuccinase (D) Arginase
Description : A biochemical indication of vitamin B12 deficiency can be obtained by measuring the urinary excretion of (A) Pyruvic acid (B) Malic acid (C) Methyl malonic acid (D) Urocanic acid
Description : Laboratory diagnosis of vitamin B12 deficiency can be made by measuring the urinary excretion of (A) Xanthurenic acid (B) Formiminoglutamic acid (C) Methylmalonic acid (D) Homogentisic acid
Description : Pyridoxine deficiency can be diagnosed by measuring the urinary excretion of xanthurenic acid following a test dose of (A) Glycine (B) Histidine (C) Tryptophan (D) Pyridoxine
Description : Pyridoxine deficiency can be diagnosed by measuring urinary excretion of (A) Pyruvic acid (B) Oxaloacetic acid (C) Xanthurenic acid (D) None of these VITAMINS 119
Description : Urinary excretion of vanillyl madelic acid is increased in (A) Phaeochromocytoma (B) Cushing’s syndrome (C) Carcinoid syndrome (D) Aldosteronism
Description : The biosynthesis of both Catecholamine and serotonin require (A) Tyrosine hydroxylase (B) N-methyl transferase (C) Aromatic amino acid decarboxylase (D) Tryptophan pyrrolase
Description : Salvage of purine bases is regulated by (A) Adenosine phosphoribosyl transferase (B) Hypoxanthine guanine phosphoribosyl transferase (C) Availability of PRPP (D) None of these
Description : The enzyme required for salvage of free purine bases is (A) Adenine phosphoribosyl transferase (B) Hypoxanthine guanine phosphoribosyl transferase (C) Both (A) and (B) (D) None of these
Description : The first reaction unique to purine nucleotide synthesis is catalysed by (A) PRPP synthetase (B) PRPP glutamyl amido transferase (C) Phosphoribosyl glycinamide synthetase (D) Formyl transferase
Description : Lesch-Nyhan syndrome, the sex linked recessive disorder is due to the lack of the enzyme: (A) Hypoxanthine-guanine phosphoribosyl transferse (B) Xanthine oxidase (C) Adenine phosphoribosyl transferase (D) Adenosine deaminase
Description : Conversion of inosine monophosphate to xanthine monophosphate is catalysed by (A) IMP dehydrogenase (B) Formyl transferase (C) Xanthine-guanine phosphoribosyl transferase (D) Adenine phosphoribosyl transferase
Description : Vitamin B12 deficiency can be diagnosed by urinary excretion of (A) Pyruvate (B) Methylmalonate (C) Malate (D) Lactate
Description : Pyridoxine deficiency can be diagnosed by measuring urinary excretion of (A) Pyruvic acid (B) Oxaloacetic acid (C) Xanthurenic acid (D) None of these
Last Answer : (C) Xanthurenic acid
Description : Acetyl CoA required for extra mitochondrial fatty acid synthesis is produced by (A) Pyruvate dehydrogenase complex (B) Citrate lyase (C) Thiolase (D) Carnitine-acyl transferase
Description : Pentosuria is a rare hereditary disease is characterized by increased urinary excretion of (A) L-xylulose (B) Xylitol (C) Xylulose 5-phosphate (D) Ribose 5-phosphate
Description : All the following statements about phenylketonuria are correct except (A) Phenylalanine cannot be converted into tyrosine (B) Urinary excretion of phenylpyruvate and phenyllactate is increased (C) It ... diet (D) It leads to decreased synthesis of thyroid hormones, catecholamines and melanin
Description : The rate limiting step in catecholamine synthesis is catalysed by (A) Phenylalanine hydroxylase (B) Tyrosine hydroxylase (C) Dopa decarboxylase (D) Phenylethanolamine N-methyl transferase
Description : In the synthetic pathway of epinephrine, disulfiram (antabuse) inhibits the enzyme: (A) Tyrosine hydroxylase (B) Dopamine β-hydroxylase (C) DOPA decarboxylase (D) N-methyl transferase
Description : All of the following statements about allopurinol are true except (A) It is a structural analogue of uric acid (B) It can prevent uric acid stones in the kidneys (C) It increases the urinary excretion of xanthine and hypoxanthine (D) It is a competitive inhibitor of xanthine oxidase
Description : All of the following statements about primary gout are true except (A) Uric acid stones may be formed in kidneys (B) Arthritis of small joints occurs commonly (C) Urinary excretion of uric acid is decreased (D) It occurs predominantly in males
Description : A characteristic of pheochromocytoma is elevated urinary excretion of (A) Dopamine (B) Tyrosine (C) Vinylmandelic acid (D) Phenylalanine
Description : Which of the following statements regarding hypercalcemia are true? A. The symptoms of hypercalcemia may mimic some symptoms of hyperglycemia. B. Metastatic breast cancer is an unusual cause of ... fluid volume deficit. E. Urinary calcium excretion may be increased by vigorous volume repletion.
Last Answer : Answer: ADE DISCUSSION: Markedly elevated serum calcium levels produce polydipsia, polyuria, and thirst. Vigorous volume repletion and saline diuresis correct the extracellular fluid volume ... , from bony metastasis. The calcitonin effect on calcium is diminished with repeat administrations
Description : The following enzymes on the left are responsible for the synthesis of the neurotransmitters on the right: a. monoamine oxidase: noradrenaline b. cholinesterase: acetylcholine c. catechol-o-methyl transferase: dopamine d. dopa decarboxylase: adrenaline
Last Answer : dopa decarboxylase: adrenaline
Description : The rate limiting enzyme in the synthesis of catecholamines is: A. Tyrosine hydroxylase B. Dopa decarboxylase C. Dopamine β-hydroxylase D. Noradrenaline N-methyl transferase
Last Answer : A. Tyrosine hydroxylase
Description : An important finding in glycinuria is (A) Excess excretion of oxalate in the urine (B) Deficiency of enzyme glycinase (C) Significantly increased serum glycine level (D) Defect in renal tubular reabsorption of glycine
Description : During compensation of respiratory alkalosis, all the following changes occur except (A) Decreased secretion of hydrogen ions by renal tubules (B) Increased excretion of sodium in urine (C) Increased excretion of bicarbonate in urine (D) Increased excretion of ammonia in urine
Description : Enzymic deficiency in β-aminoisobutyric aciduria is (A) Adenosine deaminase (B) Xanthine oxidase (C) Orotidylate decarboxylase (D) Transaminase
Description : Acute intermittent porphyria (paraoxymal porphyria) is caused due to deficiency of (A) Uroporphyrinogen I synthase (B) ALA synthase (C) Coproporphyrinogen oxidase (D) Uroporphyrinogen decarboxylase