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 : 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
Last Answer : Answer : C
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 : De novo synthesis of pyrimidine nucleotides occurs in (A) Mitochondria (B) Cytosol (C) Microsomes (D) Ribosomes
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 : 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
Last Answer : Answer : A
Description : Xanthosine monophosphate is an intermediate during de novo synthesis of (A) TMP (B) CMP (C) AMP (D) GMP
Description : The first pyrimidine nucleotide to be formed in de novo synthesis pathway is (A) UMP (B) CMP (C) CTP (D) TMP
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 : 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 : 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 : 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 : 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 : 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 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 : 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
Description : C22 and C24, fatty acids required for the synthesis of sphingolipids in brain are formed by (A) De novo synthesis (B) Microsomal chain elongation (C) Mitochondrial chain elongation (D) All of these
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 : 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 : 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 : 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 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 : De novo synthesis of purine nucleotide occurs in (A) Mitochondria (B) Cytosol (C) Microsmes (D) Ribosomes
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 : De novo synthesis of fatty acids is catalysed by a multi-enzyme complex which contains (A) One-SH group (B) Two-SH groups (C) Three-SH groups (D) Four-SH groups
Description : All following are naturally occurring nucleotides except (A) Cyclic AMP (B) ATP (C) DNA (D) Inosine monophosphate
Description : Pyrimidine biosynthesis begins with the formation from glutamine, ATP and CO2, of (A) Carbamoyl aspartate (B) Orotate (C) Carbamoyl phosphate (D) Dihydroorotate
Description : Which of the following contributes nitrogen atoms to both purine and pyrimidine rings? (A) Aspartate (B) Carbamoyl phosphate (C) CO2 (D) Glutamine
Description : Carbamoyl phosphate required for urea synthesis is formed in (A) Cytosol (B) Mitochondria (C) Both (A) and (B) (D) None of these
Description : NADPH required for fatty acid synthesis can come from (A) Hexose monophosphate shunt (B) Oxidative decarboxylation of malate (C) Extramitochondrial oxidation of isocitrate (D) All of these
Description : A vasodilating compound is produced by the decarboxylation of the amino acid: (A) Arginine (B) Aspartic acid (C) Glutamine (D) Histidine
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 : 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 : 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 : 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 : Similarity in DNA and RNA is that (a) both are polymer of nucleotides (b) both have similar pyrimidine (c) both have similar sugar (d) both are genetic material.
Last Answer : (b) both have similar pyrimidine
Last Answer : both are polymer of nucleotides
Description : n the DNA molecule, (a) the proportion of adenine in relation to thymine varies with the organism (b) there are two strands which run anti- parallel-one in 5′ → 3′ direction and other in 3′ → ... is not always equal (d) there are two strands which run parallel in the 5′ → 3′ direction.
Last Answer : (b) there are two strands which run anti- parallel-one in 5′ → 3′ direction and other in 3′ → 5′
Description : Insoinic acid is the biological precursor of (A) Cytosine and Uric acid (B) Adenylve acid and Glucine floc acid (C) Orotic acid and Uridylic acid (D) Adenosine acid Thymidine
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 : Orotic aciduria can be controlled by (A) Oral administration of orotic acid (B) Decreasing the dietary intake of orotic acid (C) Decreasing the dietary intake of pyrimidines (D) Oral administration of uridine
Description : A cofactor in the conversion of dihydroorotate to orotic acid, catalysed by the enzyme dihydroorotate dehydrogenase is (A) FAD (B) FMN (C) NAD (D) NADP
Description : Vitamin B12 has a complex ring structure (corrin ring) consisting of four (A) Purine rings (B) Pyrimidine rings (C) Pyrrole rings (D) Pteridine rings