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
Last Answer : Answer : D
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 : 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 : 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 : An allosteric inhibitor of IMP dehydrogenase is (A) AMP (B) ADP (C) GMP (D) GDP
Last Answer : Answer : C
Description : An allosteric inhibitor of adenylosuccinate synthetase is (A) AMP (B) ADP (C) GMP (D) GDP
Description : Allosteric inhibitor of glutamate dehydrogenase is (A) ATP (B) ADP (C) AMP (D) GMP
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 : PRPP synthetase is allosterically inhibited by (A) AMP (B) ADP (C) GMP (D) All of these
Description : AMP is an allosteric inhibitor of (A) PRPP synthetase (B) Adenylosucciante synthetase (C) Both (A) and (B) (D) None of these
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 : Allsoteric activator of glutamate dehydrogenase is (A) ATP (B) GTP (C) ADP and GDP (D) AMP and GMP
Description : A common substrate of HGPRTase, APRTase and PRPP glutamyl amidotransferase is (A) Ribose 5 phosphate (B) Phosphoribosyl pyrophosphate (C) Hypoxanthine (D) Adenosine
Description : Estimation of gamma glutamyl transferase is useful to detect which condition?
Last Answer : Alcohol abuse.
Description : The following abnormality in PRPP synthetase can cause primary gout: (A) High Vmax (B) Low Km (C) Resistance to allosteric inihbition. (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 : 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 : Enhanced facultative reabsorption of water by Vasopressin is mediated by (A) Cyclic AMP (B) Ca++ (C) Cyclic GMP (D) Mg++
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 catabolite repression is mediated by a catabolite gene activator protein (CAP) in conjunction with (A) AMP (B) GMP (C) cAMP (D) Cgmp
Description : Ring closure of formimidoimidazole carboxamide ribosyl-5-phosphate yields the first purine nucleotide: (A) AMP (B) IMP (C) XMP (D) GMP
Description : A pyrimidine nucleotide is (A) GMP (B) AMP (C) CMP (D) IMP
Description : The second messenger for glucocorticoids is (A) Cyclic AMP (B) Cyclic GMP (C) Inositol triphosphate (D) No second messenger is required
Description : Second messenger for glucagons is (A) Cyclic AMP (B) Diacylglycerol (C) Cyclic GMP (D) Inositol triphosphate
Description : The second messenger for PTH is (A) Cyclic AMP (B) Cyclic GMP (C) Diacylglycerol (D) Inositol triphosphate
Description : Protein kinase C is activated by (A) Cyclic AMP (B) Cyclic GMP (C) Diacyl glycerol (D) Inositol triphosphate
Description : ACTH induces rise in (A) Cyclic AMP (B) Cyclic GMP (C) Calcium (D) Magnesium
Description : Which inactivates an enzyme by occupying its active site? (A) Competitive inhibitor (B) Allosteric inhibitor (C) Non-competitive inhibitor (D) All of these
Description : Which of the following statements about an enzyme exhibiting allosteric kinetics with cooperative interaction is false? (A) A plot of V-Vk [s] has a sigmaidal shape (B) An inhibitor may increase the ... Km and Vmax (D) Removal of allosteric inhibitor may result in hyperbolic V-S [s] plot
Description : ATP is a co-substrate as well as an allosteric inhibitor of (A) Phosphofructokinase (B) Hexokinase (C) Glucokinase (D) None of these
Description : Glucose-6-phosphate is an allosteric inhibitor of (A) Glucokinase (B) Hexokinase (C) Phosphohexose isomerase (D) None of these
Description : An allosteric inhibitor of pyruvate dehydrogenase is (A) Acetyl CoA (B) ATP (C) NADH (D) Pyruvate
Description : Cyclic AMP can be formed from (A) AMP (B) ADP (C) ATP (D) All of these
Description : The enzyme aspartate transcarbamoylase of pyrimidine biosynthesis is inhibited by (A) ATP (B) ADP (C) AMP (D) CTP
Description : UDP and UTP are formed by phosphorylation from (A) AMP (B) ADP (C) ATP (D) GTP
Description : ADP ribosylation is the mode of action of (A) Cholera toxin (B) Acetyl choline (C) Muscerinic receptors (D) Cyclic AMP
Description : Standard free energy (∆G°) of hydrolysis of ADP to AMP + Pi is (A) –43.3 KJ/mol (B) –30.5 KJ/mol (C) –27.6 KJ/mol (D) –15.9 KJ/mol
Description : The enzyme phosphoenolpyruvate carboxykinase catalyses the conversion of oxaloacetate to phosphoenolpyruvate requires (A) ATP (B) ADP (C) AMP (D) GTP
Description : Phosphofructokinase key enzyme in glycolysis is inhibited by (A) Citrate and ATP (B) AMP (C) ADP (D) TMP
Description : The enzyme acyl-CoA synthase catalyses the conversion of a fatty acid of an active fatty acid in the presence of (A) AMP (B) ADP (C) ATP (D) GTP
Description : Organic nitrates relax vascular smooth muscle by (a) Increasing intracellular cyclic AMP (b) Increasing intracellular cyclic GMP (c) Decreasing intracellular cyclic AMP (d) Both (b) and (c)
Last Answer : Ans: B
Description : Cyclic nucleotides exert the following action on salt transport across intestinal mucosal cells: A. Both cyclic AMP and cyclic GMP enhance Cland HCO3 - secretion B. Cyclic AMP enhances but cyclic GMP ... Cl- reabsorption D. Both cyclic AMP and cyclic GMP enhance Na+ and Cl- reabsorption
Last Answer : A. Both cyclic AMP and cyclic GMP enhance Cland HCO3 – secreti
Description : Organic nitrates relax vascular smooth muscle by: A. Increasing intracellular cyclic GMP B. Increasing intracellular cyclic AMP C. Decreasing intracellular cyclic AMP D. Both ‘A’ and ‘C’ are correct
Last Answer : A. Increasing intracellular cyclic GMP
Description : 6.4 Several actions of growth hormone are exerted through the elaboration of: A. Cyclic AMP B. Cyclic GMP C. Somatostatin D. Insulin like growth factor-1
Last Answer : D. Insulin like growth factor-1
Description : A substance unrelated to substrate but capable of reversibly changing activity of enzyme by binding to a site other than active site is called (a) Competitive inhibitor (b) Non-competitive inhibitor (c) Catalytic inhibitor (d) Allosteric modulator/inhibitor
Last Answer : Ans. ((d))
Description : Select the correct statement abut donepezil: A. It is a topical carbonic anhydrase inhibitor used in glaucoma B. It is a catechol-'O'-methyl transferase inhibitor used as adjuvant in ... affords symptomatic improvement in Alzheimer's disease D. It is a synthetic cannabinoid with antiemetic property
Last Answer : C. It is a cerebroselective anticholinesterase that affords symptomatic improvement in Alzheimer's diseas
Description : Nucleotide found free in the cells is: (a) CAMP (b) AMP (c) ADP (d) ATP
Description : Which one of the following concerns photophosphorylation? (a) ADP + AMP ATP Light energy (b) ADP + Inorganic PO4 ATP Light energy (c) ADP + Inorganic PO4 ATP (d) AMP + Inorganic PO4 ATP
Last Answer : ) AMP + Inorganic PO4 ATP
Description : What has the most energy in its chemical bonds? a) AMP b) ADP c) ATP d) All are equal
Last Answer : ANSWER: C -- ATP