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 allosteric inhibitor of PRPP glutamyl amido transferase is (A) AMP (B) ADP (C) GMP (D) All of these
Last Answer : Answer : C
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
Last Answer : Answer : A
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 : 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 : Serum gamma glutamyl transpeptidase is raised in (A) Haemolytic jaundice (B) Myocardial infarction (C) Alcoholic hepatitis (D) Acute cholecystitis
Description : The liver enzyme which is sensitive indicator of liver cell injury and is most helpful in recognizing acute hepatocellular diseases is Options: 1) Alkaline Phosphatase 2) Aspartate aminotransferase 3) Gamma glutamyl Transpeptidase 4) Creatine Phosphokinase
Last Answer : Correct Answer: 2) Aspartate aminotransferase
Description : In primary hypothyroidism the useful estimation is of (A) T3 (B) T4 (C) TBG (D) Autoantibodies
Description : A common substrate of HGPRTase, APRTase and PRPP glutamyl amidotransferase is (A) Ribose 5 phosphate (B) Phosphoribosyl pyrophosphate (C) Hypoxanthine (D) Adenosine
Description : GMP is an allosteric inhibitor of all the following except (A) PRPP synthetase (B) PRPP glutamyl amido synthetase (C) IMP dehydrogenase (D) Adenylosuccinate synthetase
Description : PRPP glutamyl amidotransferase, the first enzyme uniquely committed to purine synthesis is feed back inhibited by (A) AMP (B) IMP (C) XMP (D) CMP
Description : Which of the following is known as bone forming enzyme? (A) Alkaline phosphatase (B) Acid phosphatase (C) Leucine aminopeptidase (D) γ-glutamyl transpeptidase
Description : Half life is a term used to describe a) The penetrating ability a gamma source b) Half the total time a gamma source will be useful c) The time taken for the gamma source to reduce the strength by half d) The rate of decay of an X-ray tube
Last Answer : c) The time taken for the gamma source to reduce the strength by half
Description : What condition does the hemoglobin test detect?
Last Answer : red blood cells
Description : Let G(x) be the generator polynomial used for CRC checking. What is the condition that should be satisfied by G(x) to detect odd number of bits in error? a. G(x) contains more than two terms b. G(x) does ... exceeding the frame length c. 1+x is a factor of G(x) d. G(x) has an odd number of terms
Last Answer : c. 1+x is a factor of G(x)
Description : Protective relays are devices that detect abnormal conditions in electrical circuits by measuring (a) current during abnormal condition (b) voltage during abnormal condition (c) constantly the electrical quantities which differ during normal and abnormal conditions (d) none of the above
Last Answer : (c) constantly the electrical quantities which differ during normal and abnormal conditions
Description : Aspartate amino transferase uses the following for transamination: (A) Glutamic acid and pyruvic acid (B) Glutamic acid and oxaloacetic acid (C) Aspartic acid and pyruvic acid (D) aspartic acid and keto adipic acid
Description : Myeloma cells are lacking in (A) TMP synthetase (B) Formyl transferase (C) HGPRT (D) All of these
Description : Erythromycin binds to 50 S ribosomal sub unit and (A) Inhibits binding of amino acyl tRNA (B) Inhibits Peptidyl transferase activity (C) Inhibits translocation (D) Causes premature chain termination
Description : Peptidyl transferase activity of 50 S ribosomal subunits is inhibited by (A) Rifampicin (B) Cycloheximide (C) Chloramphenicol (D) Erythromycin
Description : After formation of a peptide bond, mRNA is translocated along the ribosome by (A) eEF-1 and GTP (B) eEF-2 and GTP (C) Peptidyl transferase and GTP (D) Peptidyl transferase and ATP
Description : Peptidyl transferase activity is present in (A) 40 S ribosomal subunit (B) 60 S ribosomal subunit (C) eEF-2 (D) Amino acyl tRNA
Description : An alternate substrate for orotate phosphoribosyl transferase is (A) Allopurinol (B) Xanthine (C) Hypoxanthine (D) Adenine
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 : Complete absence of hypoxanthine guanine phospharibosyl transferase causes (A) Primary gout (B) Immunodeficiency (C) Uric acid stones (D) Lesh-Nyhan syndrome
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 : 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 : 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 : Defective enzyme in Hurler’s syndrome is (A) α-L-diuronidase (B) Iduronate sulphatase (C) Arylsulphatase B (D) C-acetyl transferase
Description : Peptidyl transferase activity is located in (A) Elongation factor (B) A charged tRNA molecule (C) Ribosomal protein (D) A soluble cytosolic protein
Description : Erythromycin acts on ribosomes and inhibit (A) Formation of initiation complex (B) Binding of aminoacyl tRNA (C) Peptidyl transferase activity (D) Translocation
Description : Streptomycin prevents synthesis of polypeptide by (A) Inhibiting initiation process (B) Releasing premature polypeptide (C) Inhibiting peptidyl transferase activity (D) Inhibiting translocation
Description : In prokaryotes, chloramphenicol (A) Causes premature release of the polypeptide chain (B) Causes misreading of the mRNA (C) Depolymerises DNA (D) Inhibits peptidyl transferase activity
Description : Translocation of the newly formed peptidyl tRNA at the A site into the empty P site involves (A) EF-II, GTP (B) EF-I, GTP (C) EF-I, GDP (D) Peptidyl transferase, GTP
Description : The α-amino group of the new amino acyl tRNA in the A site carries out a nucleophilic attack on the esterified carboxyl group of the peptidyl tRNA occupying the P site. This reaction is catalysed by (A) DNA polymerase (B) RNA polymerase (C) Peptidyl transferase (D) DNA ligase
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 : 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
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 : 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 : Insulin regulates fatty acid synthesis by (A) Dephosphorylating of acetyl CoA carboxylase (B) Activating phosphorylase (C) Inhibiting malonyl CoA formation (D) Controlling carnitine-Acyl CoA transferase activity
Description : The rate limiting step in catecholamine synthesis is catalysed by (A) Phenylalanine hydroxylase (B) Tyrosine hydroxylase (C) Dopa decarboxylase (D) Phenylethanolamine N-methyl transferase
Description : The biosynthesis of both Catecholamine and serotonin require (A) Tyrosine hydroxylase (B) N-methyl transferase (C) Aromatic amino acid decarboxylase (D) Tryptophan pyrrolase
Description : In the synthetic pathway of epinephrine, disulfiram (antabuse) inhibits the enzyme: (A) Tyrosine hydroxylase (B) Dopamine β-hydroxylase (C) DOPA decarboxylase (D) N-methyl transferase
Description : Ceruloplasmin shows the activity (A) As ferroxidase (B) As reductase (C) As ligase (D) As transferase
Description : A deficiency of copper effects the formation of normal collagen by reducing the activity of which of the following enzyme? (A) Prolyl hydroxylase (B) Lysyl oxidase (C) Lysyl hydroxylase (D) Glucosyl transferase
Description : Bilirubin UDP-glucuronyl transferase is absent from liver in (A) Crigler-Najjar syndrome, type I (B) Gilbert’s disease (C) Crigler-Najjar syndrome, type II (D) Rotor’s syndrome
Description : Iron is a component of (A) Hemoglobin (B) Ceruloplasmin (C) Transferase (D) Transaminase
Description : The enzyme regulating extramitochondrial fatty acid synthesis is (A) Thioesterase (B) Acetyl CoA carboxylase (C) Acyl transferase (D) Multi-enzyme complex