Description : Hyperammonaemia type I results from congenital absence of (A) Glutamate dehydrogenase (B) Carbamoyl phosphate synthetase (C) Ornithine transcarbamoylase (D) None of these
Last Answer : Answer : B
Description : Control of urea cycle involves the enzyme: (A) Carbamoyl phosphate synthetase (B) Ornithine transcarbamoylase (C) Argininosuccinase (D) Arginase
Last Answer : Answer : A
Description : The metabolite which sustains urea cycle is (A) Ornithine (B) Citrulline (C) Carbamoyl phosphate (D) n-acetyl glutamate
Last Answer : Answer : C
Description : Carbamoyl phosphate synthetase structure is marked by change in the presence of (A) N-Acetyl glutamate (B) N-Acetyl Aspartate (C) Neuraminic acid (D) Oxalate
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
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 : 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
Last Answer : Answer : D
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 : 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 : Enzyme deficient in Hyperammonemia type II is (A) Glutamine synthetase (B) Glutaminase (C) Ornithine transcarbamoylase (D) Carbamoylphosphate synthetase
Description : In urea synthesis, the amino acid functioning solely as an enzyme activator: (A) N-acetyl glutamate(B) Ornithine (C) Citrulline (D) Arginine
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 important finding in Hyperammonemia type II is (A) Increased serum gluatmine level (B) Enlarged liver (C) Mental retardation (D) Increased carbamoyl phosphate synthetase level
Description : An enzyme of pyrimidine nucleotides biosynthesis regulated at the genetic level by apparently coordinate repression and derepression is (A) Carbamoyl phosphate synthetase (B) Dihydroorotate dehydrogenase (C) Thymidine kinase (D) Deoxycytidine kinase
Description : The enzyme carbamoyl phosphate synthetase requires (A) Mg++ (B) Ca++ (C) Na+ (D) K+
Description : An enzyme which is excreted in urine is (A) Lactase dehydrogenase (B) Amylase (C) Ornithine transcarbamoylase (D) None of these
Description : Cytosolic carbamoyl phosphate synthetase is activated by (A) Glutamine (B) PRPP (C) ATP (D) Aspartate
Description : Cytosolic carbamoyl phosphate synthetase is inhibited by (A) UTP (B) CTP (C) PRPP (D) TMP
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 : CTP synthetase forms CTP from (A) CDP and inorganic phosphate (B) CDP and ATP (C) UTP and glutamine (D) UTP and glutamate
Description : All the following statements about charging of tRNA are correct except (A) It is catalysed by amino acyl tRNA synthetase (B) ATP is converted into ADP and Pi in this reaction (C) The enzyme recognizes the tRNA and the amino acid (D) There is a separate enzyme for each tRNA
Description : Conversion of deoxyuridine monophosphate to thymidine monophosphate is catalysed by the enzyme: (A) Ribonucleotide reductase (B) Thymidylate synthetase (C) CTP synthetase (D) Orotidylic acid decarboxylase
Description : Riboflavin is a coenzyme in the reaction catalysed by the enzyme (A) Acyl CoA synthetase (B) Acyl CoA dehydrogenase (C) β-Hydroxy acyl CoA (D) Enoyl CoA dehydrogenase
Description : Congenital deficiency of ornithine transcarbamoylase causes (A) Hyperammonaemia type I (B) Hyperammonaemia type II (C) Hyperornithinaemia (D) Citrullinaemia
Description : In gluconeogensis, an allosteric activator required in the synthesis of oxaloacetate from bicarbonate and pyruvate, which is catalysed by the enzyme pyruvate carboxylase is (A) Acetyl CoA (B) Succinate (C) Isocitrate (D) Citrate
Description : Carboxylation of acetyl-CoA to malonylCoA requires the enzyme: (A) Acetyl-CoA carboxylase (B) Pyruvate carboxylase (C) Acetyl transacylase (D) Acyl CoA-synthetase
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 : 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 : The decarboxylation reaction in HMP shunt is catalysed by (A) Gluconolactone hydrolase (B) 6-Phosphogluconate dehydrogenase (C) 6-Phosphogluconate decarboxylase (D) Transaldolase
Description : Two nitrogen of the pyrimidines ring are obtained from (A) Glutamine and Carbamoyl-p (B) Asparate and Carbamoyl-p (C) Glutamate and NH3 (D) Glutamine and NH3
Description : The hydrolysis of Glucose-6-phosphate is catalysed by a specific phosphatase which is found only in (A) Liver, intestines and kidneys (B) Brain, spleen and adrenals (C) Striated muscle (D) Plasma
Last Answer : A
Description : Which enzyme is concerned with transfer of electrons? (A) Desmolase (B) Hydrolase (C) Dehydrogenase (D) Transaminase
Description : Galactose 1-phosphate is converted to uridine diphosphate galactose, the reaction is catalysed by the enzyme: (A) Glactokinase (B) Galactose 1-phosphate uridyl transferase (C) Uridine diphospho galactose 4-epimerase (D) UDP glucose pyrophosphorylase
Description : Glucose 6-phosphate is converted to glucose 1-phosphate in a reaction catalysed by the enzyme phosphoglucomutase, which is (A) Phosphorylated (B) Dephosphorylated (C) Phosphorylated-dephosphorylated (D) Phosphorylated-dephosphorylatedrephosphorylated
Description : An enzyme which acts as allosteric regulator and sensitive to both phosphate concentration and to the purine nucleotides is (A) PRPP synthetase (B) PRPP glutamyl midotransferase (C) HGPR Tase (D) Formyl transferase
Description : The enzyme that converts glucose to glucose-6-phosphate is (A) Phosphatase (B) Hexokinase (C) Phosphorylase (D) Glucose synthetase
Description : L-glutamic acid is subjected to oxidative deaminition by (A) L-amino acid dehydrogenase (B) L-glutamate dehydrogenase (C) Glutaminase (D) Glutamine synthetase
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 : Phosphorylation of adenosine to AMP is catalysed by (A) Adenosine kinase (B) Deoxycytidine kinase (C) Adenylosuccinase (D) Adenylosuccinate synthetase
Description : HMG-CoA is converted to mevalonate by reduction catalysed by (A) HMG-CoA synthetase (B) HMG-CoA reductase (C) Mevalonate kinase (D) Thiolase
Description : Synthesis of phosphatidylinositol by transfer of inositol to CDP diacylglycerol is catalysed by the enzyme: (A) CTP phosphatidate cytidyl transferase (B) Phosphatidate phosphohydrolase (C) CDP-diacylglycerol inositol transferase (D) Choline kinase
Description : A key substance in the committed step of pyrimidines biosynthesis is (A) Ribose-5-phosphate (B) Carbamoyl phosphate (C) ATP (D) Glutamine
Description : The two nitrogen of the pyrimidine ring are contributed by (A) Ammonia and glycine (B) Asparate and carbamoyl phosphate (C) Glutamine and ammonia (D) Aspartate and ammonia
Description : Pyrimidine biosynthesis begins with the formation from glutamine, ATP and CO2, of (A) Carbamoyl aspartate (B) Orotate (C) Carbamoyl phosphate (D) Dihydroorotate
Description : The highest energy level is present amongst the following in (A) 1, 3-Biphosphoglycerate (B) Creatine phosphate (C) Carbamoyl phosphate (D) Phosphoenol pyruvate
Description : Which of the following contributes nitrogen atoms to both purine and pyrimidine rings? (A) Aspartate (B) Carbamoyl phosphate (C) CO2 (D) Glutamine
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 : Carbamoyl phosphate required for urea synthesis is formed in (A) Cytosol (B) Mitochondria (C) Both (A) and (B) (D) None of these
Description : Conversion of pyruvate into acetyl CoA is catalysed by (A) Pyruvate dehydrogenase (B) Didrolipoyl acetyl transferase (C) Dihydrolipoyl dehydrogenase (D) All the 3 acting in concert
Description : Two molecules of acetyl-CoA condense to form acetoacetyl-CoA catalysed by (A) Thiolase (B) Kinase (C) Reductase (D) Isomerase