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 : Ring closure of formimidoimidazole carboxamide ribosyl-5-phosphate yields the first purine nucleotide: (A) AMP (B) IMP (C) XMP (D) GMP
Last Answer : Answer : B
Description : A common substrate of HGPRTase, APRTase and PRPP glutamyl amidotransferase is (A) Ribose 5 phosphate (B) Phosphoribosyl pyrophosphate (C) Hypoxanthine (D) Adenosine
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 : 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 : 6-Mercapto purine inhibits the conversion of (A) IMP→ XMP (B) Ribose 5 phosphate → PRPP (C) PRPP → 5-phospho →β -D-ribosylamine (D) Glycinamide ribosyl 5-phosphate → formylglycinamide ribosyl-5-phosphate
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 : In the biosynthesis of purine nucleotides the AMP feed back regulates (A) Adenylosuccinase (B) Adenylosuccinate synthetase (C) IMP dehydrogenase (D) HGPR Tase
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 : A pyrimidine nucleotide is (A) GMP (B) AMP (C) CMP (D) IMP
Description : A purine nucleotide is (A) AMP (B) UMP (C) CMP (D) TMP
Description : PRPP synthetase is allosterically inhibited by (A) AMP (B) ADP (C) GMP (D) All 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 : 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 : The enzyme aspartate transcarbamoylase of pyrimidine biosynthesis is inhibited by (A) ATP (B) ADP (C) AMP (D) CTP
Description : Phosphofructokinase key enzyme in glycolysis is inhibited by (A) Citrate and ATP (B) AMP (C) ADP (D) TMP
Description : Aspartate transcarbamoylase is inhibited by (A) CTP (B) PRPP (C) ATP (D) TMP
Description : Cytosolic carbamoyl phosphate synthetase is inhibited by (A) UTP (B) CTP (C) PRPP (D) TMP
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 : Pyrimidine and purine nucleoside biosynthesis share a common precursor: (A) PRPP (B) Glycine (C) Fumarate (D) Alanine
Description : AMP is an allosteric inhibitor of (A) PRPP synthetase (B) Adenylosucciante synthetase (C) Both (A) and (B) (D) None of these
Description : Cancer cells may become resistant to amethopterin by (A) Developing mechanisms to destroy amethopterin (B) Amplification of dihydrofolate reducatse gene (C) Mutation in the dihydrofolate reductase ... is no longer inhibited by amethopterin (D) Developing alternate pathway of thymidylate synthesis
Description : Purine biosynthesis is inhibited by (A) Aminopterin (B) Tetracyclin (C) Methotrexate (D) Chloramphenicol
Description : The first pyrimidine nucleotide to be formed in de novo synthesis pathway is (A) UMP (B) CMP (C) CTP (D) TMP
Description : Tetrahydrofolate is required as a coenzyme for the synthesis of (A) UMP (B) CMP (C) TMP (D) All of these
Description : Amethopterin and aminopterin decrease the synthesis of (A) TMP (B) UMP (C) CMP (D) All of these
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 : An allosteric inhibitor of IMP dehydrogenase is (A) AMP (B) ADP (C) GMP (D) GDP
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 : Action of glycogen synthase is inhibited by (A) Insulin (B) Glucose (C) Mg2+ (D) Cyclic AMP
Description : Synthesis of GMP and IMP requires the following: (A) NH3 NAD+, ATP (B) Glutamine, NAD+, ATP (C) NH3, GTP, NADP+ (D) Glutamine, GTP, NADP+
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 : Mitochondrial protein synthesis is inhibited by (A) Cycloheximide (B) Chloramphenicol (C) Diptheria toxin (D) None of these
Description : Porphyrin synthesis is inhibited in (A) Mercury poisoning (B) Lead poisoning (C) Manganese poisoning (D) Barium poisoning
Description : Synthesis of prostaglandins is inhibited by (A) Glucocorticoids (B) Aspirin (C) Indomethacin (D) All of these
Description : The synthesis of glucose from pyruvate by gluconeogenesis (A) Requires the participation of biotin (B) Occurs exclusively in the cytosol (C) Is inhibited by elevated level of insulin (D) Requires oxidation/reduction of FAD
Last Answer : A
Description : All of the following statements about the enzymic complex that carries out the synthesis of ATP during oxidative phosphorylation are correct except (A) It is located on the matrix side of the inner ... inhibited by oligomycin (C) It can exhibit ATPase activity (D) It can bind molecular O2
Last Answer : D
Description : Synthesis of prostaglandinsis is inhibited by (A) Aspirin (B) Arsenic (C) Fluoride (D) Cyanide
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 : 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 : 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 : De novo synthesis of purine nucleotide occurs in (A) Mitochondria (B) Cytosol (C) Microsmes (D) Ribosomes
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 : In which of the following types of enzymes an inducer is not required? (A) Inhibited enzyme (B) Cooperative enzyme (C) Allosteric enzyme (D) Constitutive enzyme
Description : An allosteric enzyme is generally inhibited by (A) Initial substrate of the pathway (B) Substrate analogues (C) Product of the reaction catalysed by allosteric enzyme (D) Product of the pathway
Description : A demonstrable inducer is absent in (A) Allosteric enzyme (B) Constitutive enzyme (C) Inhibited enzyme (D) Co-operative enzyme ENZYMES 141