Description : In urea synthesis, the amino acid functioning solely as an enzyme activator: (A) N-acetyl glutamate(B) Ornithine (C) Citrulline (D) Arginine
Last Answer : Answer : A
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
Last Answer : Answer : B
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
Last Answer : Answer : C
Description : Control of urea cycle involves the enzyme: (A) Carbamoyl phosphate synthetase (B) Ornithine transcarbamoylase (C) Argininosuccinase (D) Arginase
Description : Hyperammonaemia type I results from congenital absence of (A) Glutamate dehydrogenase (B) Carbamoyl phosphate synthetase (C) Ornithine transcarbamoylase (D) None of these
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 amino acid not involved in urea cycle is (A) Arginine (B) Histidine (C) Ornithine (D) Citrulline
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 : 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 : An aneplerotic reaction which sustains the availability of oxaloacetate is the carboxylation of (A) Glutamate (B) Pyruvate (C) Citrate (D) Succinate
Last Answer : B
Description : The amino acid which contains a guanidine group is (A) Histidine (B) Arginine (C) Citrulline (D) Ornithine
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 : Carbamoyl phosphate required for urea synthesis is formed in (A) Cytosol (B) Mitochondria (C) Both (A) and (B) (D) None of these
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 : Citrulline is an intermediate of (A) TCA cycle (B) Urea cycle (C) Pentose cycle (D) Calvin cycle
Description : N-Formiminoglutamate is a metabolite of (A) Glutamate (B) Histidine (C) Tryptophan (D) Methionine
Description : The following 4 amino acids are required for completion of urea cycle except (A) Aspartic acid (B) Arginine (C) Ornithine (D) Glycine
Last Answer : Answer : D
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 : Two nitrogen atoms of Urea in the urea cycle come from (A) NH3 (B) One from NH3 and one from aspartate (C) One from NH3 and one from glutamate (D) One from NH3 and one from alanine
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 : 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
Description : The following is not true of the cytochrome P450 isoenzyme CYP2D6: A. It generates the hepatotoxic metabolite N-acetyl benzoquinone immine from paracetamol B. It is involved in demethylation of ... for poor capacity to hydroxylate many drugs including metoprolol D. It is inhibited by quinidine
Last Answer : A. It generates the hepatotoxic metabolite N-acetyl benzoquinone immine from paracetamol
Description : N-acetyl cysteine is beneficial in acute paracetamol poisoning because: A. It reacts with paracetamol to form a nontoxic complex B. It inhibits generation of the toxic metabolite of ... scavenger D. It replenishes hepatic glutathione which in turn binds the toxic metabolite of paracetamol
Last Answer : D. It replenishes hepatic glutathione which in turn binds the toxic metabolite of paracetamol
Last Answer : A. It generates the hepatotoxic metabolite N-acetyl benzoquinone immine from paracetamo
Description : A metabolite which is common to pathways of cholesterol biosynthesis from acetyl-CoA and cholecalciferol formation from cholesterol is (A) Zymosterol (B) Lumisterol (C) Ergosterol (D) 7 Dehydrocholesterol
Description : Which of the following metabolite integrates glucose and fatty acid metabolism? (A) Acetyl CoA (B) Pyruvate (C) Citrate (D) Lactate
Last Answer : A
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 : A key substance in the committed step of pyrimidines biosynthesis is (A) Ribose-5-phosphate (B) Carbamoyl phosphate (C) ATP (D) Glutamine
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 : 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
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 : 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 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 : 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 : Which of the following contributes nitrogen atoms to both purine and pyrimidine rings? (A) Aspartate (B) Carbamoyl phosphate (C) CO2 (D) Glutamine
Description : The enzyme carbamoyl phosphate synthetase requires (A) Mg++ (B) Ca++ (C) Na+ (D) K+
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 : Which of the following is present as a marker in lysosomal enzymes to direct them to their destination? (A) Glucose-6-phosphate (B) Mannose-6-phosphate (C) Galactose-6-phosphate (D) N-Acetyl neuraminic acid
Description : The four nitrogen atoms of purines are derived from (A) Urea and NH3 (B) NH3, Glycine and Glutamate (C) NH3, Asparate and Glutamate (D) Aspartate, Glutamine and Glycine
Description : The 2 nitrogen atoms in urea are contributed by (A) Ammonia and glutamate (B) Glutamine and glutamate (C) Ammonia and aspartate (D) Ammonia and alanine
Description : CTP synthetase forms CTP from (A) CDP and inorganic phosphate (B) CDP and ATP (C) UTP and glutamine (D) UTP and glutamate
Description : Pyridoxal phosphate is a coenzyme for (A) Glutamate oxaloacetate transaminase (B) Glutamate pyruvate transaminase (C) Tyrosine transaminase (D) All of these
Description : All of the following are required for synthesis of glutamine except (A) Glutamate (B) Ammonia (C) Pyridoxal phosphate (D) ATP
Description : All of the following are required for synthesis of alanine except (A) Pyruvate (B) α-ketoglutarate (C) Glutamate (D) Pyridoxal phosphate
Description : The principal action of insulin in adipose tissue is to inhibit the activity of the (A) Hormone sensitive lipoprotein lipase (B) Glycerol phosphate acyltransferase (C) Acetyl-CoA carboxylase (D) Pyruvate dehydrogenase