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
Last Answer : Answer : C
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 available PRPP is used preferentially for (A) De novo synthesis of purine nucleotides (B) De novo synthesis of pyrimidine nucleotides (C) Salvage of purine bases (D) Salvage of pyrimidine bases
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
Last Answer : Answer : D
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
Last Answer : Answer : A
Description : Nucleotides required for the synthesis of nucleic acids can be obtained from (A) Dietary nucleic acids and nucleotides (B) De novo synthesis (C) Salvage of pre-existing bases and nucleosides (D) De novo synthesis and salvage
Description : Complete absence of hypoxanthine guanine phospharibosyl transferase causes (A) Primary gout (B) Immunodeficiency (C) Uric acid stones (D) Lesh-Nyhan syndrome
Description : For de novo synthesis of purine nucleotides, aspartate provides (A) Nitrogen 1 (B) Nitrogen 3 (C) Nitrogen 7 (D) Nitrogen 9
Description : For de novo synthesis of purine nucleotides, glycine provides (A) One nitrogen atom (B) One nitrogen and one carbon atom (C) Two carbon atoms (D) One nitrogen and two carbon atoms
Description : The nitrogen atoms for de novo synthesis of purine nucleotides are provided by (A) Aspartate and glutamate (B) Aspartate and glycine (C) Aspartate, glutamine and glycine (D) Aspartate, glutamate and glycine
Description : 5-Phosphoribosyl-1-pyrophosphate is required for the synthesis of (A) Purine nucleotides (B) Pyrimidine nucleotides (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
Last Answer : Answer : B
Description : An alternate substrate for orotate phosphoribosyl transferase is (A) Allopurinol (B) Xanthine (C) Hypoxanthine (D) Adenine
Description : During de novo synthesis of pyrimidine nucleotides, the first ring compound to be formed is (A) Carbamoyl aspartic acid (B) Dihydro-orotic acid (C) Orotic acid (D) Orotidine monophosphate
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 : De novo synthesis and oxidation of fatty acids differ in the following respect: (A) Synthesis occurs in cytosol and oxidation in mitochondria (B) Synthesis is decreased and oxidation increased by ... synthesis and FAD in oxidation (D) Malonyl CoA is formed during oxidation but not during synthesis
Description : The end product of purine catabolism in man is (A) Inosine (B) Hypoxanthine (C) Xanthine (D) Uric acid
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 : 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 occurs in (A) Mitochondria (B) Cytosol (C) Microsomes (D) Ribosomes
Description : De novo synthesis of purine nucleotide occurs in (A) Mitochondria (B) Cytosol (C) Microsmes (D) Ribosomes
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 : Free purine bases which can be salvaged are (A) Adenine and guanine (B) Adenine and hypoxanthine (C) Guanine and hypoxanthine (D) Adenine, guanine and hypoxanthine
Description : Purines: a. include guanine b. are metabolized to uric acid c. are mainly synthesized in the liver d. all above
Last Answer : all above
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 : Following nucleotides are called purines a. adenine b. guanine c. both d. none
Last Answer : both
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 : 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 : Orotic aciduria type II reflects the deficiency of the enzyme: (A) Orotate phosphoribosyl transferase (B) Orotidylate decarboxylase (C) Dihydroorotase (D) Dihydroorotate 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 : The key substance in the synthesis of purine, phosphoribosyl pyrophosphate is formed by (A) α-D-ribose 5-phosphate (B) 5-phospho β-D-ribosylamine (C) D-ribose (D) Deoxyribose
Description : A 73 year old male presented with an acute attack of gout in his left knee. What is the most likely underlying metabolic cause? 1) decreased renal excretion of uric acid 2) endogenous overproduction of uric acid 3) excessive dietary purine intake 4) lactic acidosis 5) starvation
Last Answer : Answers-1 The aetiology of gout can broadly be divided into cases where there is underexcretion of urate via the kidney (90%) or endogenous overproduction of uric acid (10%) although in practical ... diuretic use. Excessive dietary intake of purines is unlikely to be the main cause in this case.
Description : A common substrate of HGPRTase, APRTase and PRPP glutamyl amidotransferase is (A) Ribose 5 phosphate (B) Phosphoribosyl pyrophosphate (C) Hypoxanthine (D) Adenosine
Description : One functional sub-unit of multi-enzyme complex for de novo synthesis of fatty acids contains (A) One —SH group (B) Two —SH groups (C) Three —SH groups (D) Four —SH groups FATS AND FATTY ACID METABOLISM 87
Description : De novo synthesis of fatty acids requires all of the following except (A) Biotin (B) NADH (C) Panthothenic acid (D) ATP
Description : Acetyl CoA from mitochondria is transferred to cytoplasm for the de novo synthesis of fatty acid, by which enzyme?
Last Answer : ATP citrate lyase.
Description : What is the rate limiting enzyme of de novo synthesis of fatty acid?
Last Answer : Acetyl CoA carboxylase.
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 : Inherited deficiency of purine nucleoside phosphorylase causes (A) Dwarfism (B) Mental retardation (C) Immunodeficiency (D) Gout
Description : In humans, the principal metabolic product of pyrimidines is (A) Uric acid (B) Allantoin (C) Hypoxanthine (D) β-alanine
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 : The first pyrimidine nucleotide to be formed in de novo synthesis pathway is (A) UMP (B) CMP (C) CTP (D) TMP
Description : Xanthosine monophosphate is an intermediate during de novo synthesis of (A) TMP (B) CMP (C) AMP (D) GMP
Description : Inosine monophophate is an intermediate during the de novo synthesis of (A) AMP and GMP (B) CMP and UMP (C) CMP and TMP (D) All of these
Description : All the following statements about acetyl CoA carboxylase are true except (A) It is required for de novo synthesis of fatty acids (B) It is required for mitochondrial elongation of fatty acids ( ... for microsomal elongation of fatty acids (D) Insulin converts its inactive form into its active form
Description : Formation of acetyl CoA from pyruvate for de novo synthesis of fatty acids requires (A) Pyruvate dehydrogenase complex (B) Citrate synthetase (C) ATP citrate lyase (D) All of these
Description : Acetyl CoA required for de novo synthesis of fatty acids is obtained from (A) Breakdown of existing fatty acids (B) Ketone bodies (C) Acetate (D) Pyruvate
Description : The maximum possible chain length of fatty acids formed in the pathway of de novo synthesis is (A) 16 Carbon atoms (B) 18 Carbon atoms (C) 20 Carbon atoms (D) 24 Carbon atoms