Description : Control of urea cycle involves the enzyme: (A) Carbamoyl phosphate synthetase (B) Ornithine transcarbamoylase (C) Argininosuccinase (D) Arginase
Last Answer : Answer : A
Description : An enzyme common to de novo synthesis of pyrimidine nucleotides and urea is (A) Urease (B) Carbamoyl phosphate synthetase (C) Aspartate transcarbamoylase (D) Argininosuccinase
Last Answer : Answer : B
Description : The following enzyme of urea cycle is present in cytosol: (A) Argininosuccinic acid synthetase (B) Argininosuccinase (C) Arginase (D) All of these
Last Answer : Answer : D
Description : Absence of the enzyme argininosuccinate synthetase causes (A) Argininosuccinic aciduria (B) Hyperargininemia (C) Tricorrhexis nodosa (D) Citrullinemia
Description : Enzyme deficient in Hyperammonemia type II is (A) Glutamine synthetase (B) Glutaminase (C) Ornithine transcarbamoylase (D) Carbamoylphosphate synthetase
Last Answer : Answer : C
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 : Hyperammonaemia type I results from congenital absence of (A) Glutamate dehydrogenase (B) Carbamoyl phosphate synthetase (C) Ornithine transcarbamoylase (D) None of these
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 : Deficiency of urea cycle enzymes results into accumulation of citrulline argininosuccinate arginine in the liver resulting in increasing concentration of …….. in the blood. (A) Calcium (B) Sodium (C) Ammonia (D) Lipid
Description : Elevated blood argininosuccinate level is found in (A) Hyperargininemia (B) Argininosuccinic aciduria (C) Citrullinemia (D) Tyrosinosis
Description : Congenital deficiency of ornithine transcarbamoylase causes (A) Hyperammonaemia type I (B) Hyperammonaemia type II (C) Hyperornithinaemia (D) Citrullinaemia
Description : Increased urinary excretion of orotic acid can occur in deficiency of (A) Orotate phosphoribosyl transferase (B) OMP decarboxylase (C) Mitochondrial ornithine transcarbamoylase (D) Any of the above
Description : An enzyme which is excreted in urine is (A) Lactase dehydrogenase (B) Amylase (C) Ornithine transcarbamoylase (D) None of these
Description : Enzyme involved in joining together two substrates is (A) Glutamine synthetase (B) Aldolase (C) Gunaine deaminase (D) Arginase
Description : In urea synthesis, the amino acid functioning solely as an enzyme activator: (A) N-acetyl glutamate(B) Ornithine (C) Citrulline (D) Arginine
Description : De novo synthesis of pyrimidine nucleotides is regulated by (A) Carbamoyl phosphate synthetase (B) Aspartate transcarbamoylase (C) Both (A) and (B) (D) None of these
Description : Cytosolic and mitochondrial carbamoyl phosphate synthetase have the following similarity: (A) Both use ammonia as a substance (B) Both provide carbamoyl phosphate for urea synthesis (C) Both require N-acetylglutamate as an activator (D) Both are allosteric enzymes
Description : In ornithine cycle, enzyme arginase breaks down arginine into
Last Answer : In ornithine cycle, enzyme arginase breaks down arginine into A. Citrulline and ammonia B. Ornithine ... C. Ornithine and urea D. Citruline and urea
Description : ATP is required in following reactions of urea cycle: (A) Synthesis of carbamoyl phosphate and citrulline (B) Synthesis of citrulline and argininosuccinate (C) Synthesis of argininosuccinate and arginine (D) Synthesis of carbamoyl phosphate and argininosuccinate
Description : Urea is produced physiologically by the action of the enzyme: (A) Urease (B) Glutaminase (C) Arginase (D) None of these
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 of the following enzymes are unique to purine nucleotide synthesis except (A) PRPP synthetase (B) PRPP glutamyl amido transferase (C) Adenylosuccinate synthetase (D) IMP dehydrogenase
Description : In the pathway of de novo synthesis of purine nucleotides, all the following are allosteric enzymes except (A) PRPP glutamyl amido transferase (B) Adenylosuccinate synthetase (C) IMP dehydrogenase (D) Adenylosuccinase
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
Description : The enzyme amino acyl tRNA synthetase is involved in (A) Dissociation of discharged tRNA from 80S ribosome (B) Charging of tRNA with specific amino acids (C) Termination of protein synthesis (D) Nucleophilic attack on esterified carboxyl group of peptidyl tRNA
Description : An enzyme required for the synthesis of thyroid hormones is (A) Iodinase (B) Deiodinase (C) Thyroperoxidase (D) Thyroxine synthetase
Description : The regulatory enzyme for haem synthesis is (A) ALA synthetase (B) haem synthetase (C) Both (A) and (B) (D) None of these
Description : An enzyme required for the synthesis of ketone bodies as well as cholesterol is (A) Acetyl CoA carboxylase (B) HMG CoA synthetase (C) HMG CoA reductase (D) HMG CoA lyase
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 : Neimann-Pick disease is due to the deficiency of the enzyme: (A) Hexosaminidase A and B (B) Ceramidase (C) Ceramide lactosidase (D) Sphingomyelinase CHAPTER 6 CHAPTER 6 ENZYMES
Description : The following 4 amino acids are required for completion of urea cycle except (A) Aspartic acid (B) Arginine (C) Ornithine (D) Glycine
Description : The metabolite which sustains urea cycle is (A) Ornithine (B) Citrulline (C) Carbamoyl phosphate (D) n-acetyl glutamate
Description : An amino acid not involved in urea cycle is (A) Arginine (B) Histidine (C) Ornithine (D) Citrulline
Description : Synthesis of the following enzymes is increased during starvation. (A) Digestive enzymes (B) Gluconeogenic enzymes (C) Urea cycle enzymes (D) Glucokinase
Description : The enzymes of urea synthesis are found in (A) Mitochondria only (B) Cytosol only (C) Both mitochondria and cytosol (D) Nucleus
Description : Trimethoprim inhibits bacteria without affecting mammalian cells because: A. It does not penetrate mammalian cells B. It has high affinity for bacterial but low affinity for mammalian dihydrofolate ... bacterial folate synthetase as well as dihydrofolate reductase enzymes D. All of the above
Last Answer : B. It has high affinity for bacterial but low affinity for mammalian dihydrofolate reductase enzyme
Description : The enzyme aspartate transcarbamoylase of pyrimidine biosynthesis is inhibited by (A) ATP (B) ADP (C) AMP (D) CTP
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 : 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 : Jamaican vomiting sickness is due to inactivation of the enzyme (A) Pyruvate carboxylase (B) Acyl-Co-A synthetase (C) Acyl-Co-A dehydrogense (D) Thiolase
Description : Arginase enzyme is formed by (a) Spleen (b) Liver (c) Kidney (d) All
Last Answer : (b) Liver
Description : Enzyme arginase is found in (a) Mouth cavity (b) Stomach (c) Intestine (d) Liver
Last Answer : (d) Liver
Description : Bassen-Kornzweig syndrome is due to (A) Absence of Apo-C-II (B) Defect in Apo-B synthesis (C) Absence of Apo-E (D) Absence of Apo-D
Description : The genetic defect-adenosine deaminase (ADA) deficiency may be cured permanently by (a) administering adenosine deaminase activators (b) introducing bone marrow cells producing ADA into ... replacement therapy (d) periodic infusion of genetically engineered lymphocytes having functional ADA cDNA
Last Answer : (b) introducing bone marrow cells producing ADA into cells at early embryonic stages
Description : Hormones (A) Act as coenzyme (B) Act as enzyme (C) Influence synthesis of enzymes (D) Belong to B-complex group
Description : Hemolytic anemia is caused by the deficiency of certain enzymes of the pentose phosphate pathway, the principal enzyme involved is (A) Glucose-6-phosphate dehydrogenase (B) Aldolase (C) Fructose 1, 6-bisphosphatase (D) Phosphohexose isomerase
Description : The ornithine cycle removes two waste products from the blood in liver. These products are (a) CO2 and ammonia (b) ammonia and uric acid (c) CO2 and urea (d) ammonia and urea.
Last Answer : a) CO2 and ammonia
Description : In ureotelic animals, urea is formed by (a) Krebs’ cycle (b) EM pathway (c) Ornithine cycle (d) Cori cycle.
Last Answer : (c) Ornithine cycle
Description : Conversion of ammonia to urea is done by (a) ornithine cycle (b) arginine cycle (c) fumaric cycle (d) citrulline cycle.
Last Answer : (a) ornithine cycle
Description : In ornithine cycle, which of the following wastes are removed from the blood? (a) CO2 and urea (b) Ammonia and urea (c) CO2 and ammonia (d) Urea and urine
Last Answer : (c) CO2 and ammonia