Description : Binding of RNA polymerase holoenzyme to the promoter region of lac operon is facilitated by (A) Catabolite gene activator protein (CAP) (B) cAMP (C) CAP-cAMP complex (D) None of these
Last Answer : Answer : C
Description : Lactose or its analogues act as positive regulators of lac operon by (A) Attaching to i gene and preventing its expression (B) Increasing the synthesis of catabolite gene activator protein (C) ... holoenzyme (D) Binding to repressor subunits so that the repressor cannot attach to the operator locus
Last Answer : Answer : D
Description : The enzymes encoded by z, y and a genes of lac operon are inducible, and their inducer is (A) Lactose (B) Allo-lactose (C) Catabolite gene activator protein (D) All of these
Last Answer : Answer : B
Description : Vasoconstrictor effect of ADH is mediated by (A) cAMP (B) cGMP (C) Protein kinase C (D) Angiotensin II
Description : Allsoteric activator of glutamate dehydrogenase is (A) ATP (B) GTP (C) ADP and GDP (D) AMP and GMP
Description : Enhanced facultative reabsorption of water by Vasopressin is mediated by (A) Cyclic AMP (B) Ca++ (C) Cyclic GMP (D) Mg++
Last Answer : Answer : A
Description : The best understood intracellular messenger is cyclic AMP (cAMP). Which of the following statement(s) concerning this intracellular messenger is/are correct? a. Intracellular cyclic AMP is constantly ... of adenylate cyclase d. cAMP is the only cyclic nucleotide active as an intracellular messenger
Last Answer : Answer: a, b The prototypic intracellular messenger is cAMP. To function as a mediator, the concentration of cAMP must change rapidly. In resting cells, cAMP is continuously being degraded by ... produce cGMP. Intracellular calcium ions also serve as second messengers in a large number of cells
Description : Protein kinase C is activated by (A) Cyclic AMP (B) Cyclic GMP (C) Diacyl glycerol (D) Inositol triphosphate
Description : The activity of kinins is modulated by (A) Prostaglandins (B) Ca++ (C) Increased cAMP level (D) Increased cGMP level
Description : Binding of catecholamines to α2− adrenergic receptors (A) Increases the intracellular concentration of cAMP (B) Increases the intracellular concentration of cGMP (C) Decreases the intracellular concentration of cAMP (D) Decreases the intracellular concentration of cGMP
Description : The second messenger for many hormones is (A) ATP (B) cyclic AMP (C) cGMP (D) UTP HORMONE METABOLISM 227
Description : An allosteric inhibitor of IMP dehydrogenase is (A) AMP (B) ADP (C) GMP (D) GDP
Description : An allosteric inhibitor of adenylosuccinate synthetase is (A) AMP (B) ADP (C) GMP (D) GDP
Description : An allosteric inhibitor of PRPP glutamyl amido transferase is (A) AMP (B) ADP (C) GMP (D) All of these
Description : PRPP synthetase is allosterically inhibited by (A) AMP (B) ADP (C) GMP (D) All of these
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 : 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 : ACTH induces rise in (A) Cyclic AMP (B) Cyclic GMP (C) Calcium (D) Magnesium
Description : Allosteric inhibitor of glutamate dehydrogenase is (A) ATP (B) ADP (C) AMP (D) GMP
Description : Cyclooxygenase-1 and –2 are responsible for (a) The synthesis of prostaglandins from arachidonate (b) The synthesis of leukotrienes from arachidonate (c) The conversion of ATP to cAMP (d) The metabolic degradation of cAMP (e) The conversion of GTP to cGMP
Last Answer : Ans: A
Description : Which one of the following is not a secondary messenger in hormone action? (a) cAMP (b) cGMP (c) Calcium (d) Sodium
Last Answer : d) Sodium
Description : Which of the following is transcribed during repression? (A) Structural gene (B) Promoter gene (C) Regulator gene (D) Operator gene
Description : The gene which is transcribed during repression is (A) Structural (B) Regulator (C) Promoter (D) Operator
Description : Which of the following regulates lipolysis in adipocytes? (A) Activation of fatty acid synthesis mediated by CAMP (B) Glycerol phosphorylation to prevent futile esterification of fatty acids (C) ... result of hormone stimulated increases in CAMP levels (D) Activation of CAMP production by Insulin
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 : Expression of structural genes of lac operon is affected by all the following except (A) Lactose or its analogues (B) Repressor tetramer (C) cAMP (D) CAP-cAMP complex
Description : The first protein synthesized by recombinant DNA technology was (A) Streptokinase (B) Human growth hormone (C) Tissue plasminogen activator (D) Human insulin
Description : The ‘rho’ (ρ) factor is involved (A) To increase the rate of RNA synthesis (B) In binding catabolite repressor to the promoter region (C) In proper termination of transcription (D) To allow proper initiation of transcriptide
Description : All of the following statements about uric acid are true except (A) It is a catabolite of purines (B) It is excreted by the kidneys (C) It is undissociated at pH above 5.8 (D) It is less soluble than sodium urate
Description : In pKO1 plasmid, galactose kinase gene is a reporter gene which lacks ___________ gene. a. Initiation codon b. Promoter c. Activator d. Termination
Last Answer : b. Promoter
Description : Actions of 5-HT2 receptor activation are primarily mediated by: A. Increased membrane permeability to Na+ ions B. Increased formation of cAMP C. Activation of guanylyl cyclase D. Generation of inositol trisphosphate and diacyl glycerols
Last Answer : D. Generation of inositol trisphosphate and diacyl glycerols
Description : All of the following subserve as intracellular second messengers in receptor mediated signal transduction except: A. Cyclic AMP B. Inositol trisphosphate C. Diacyl glycerols D. G proteins
Last Answer : D. G proteins
Description : As thrombin generation proceeds, the body has natural anticoagulant systems opposing further thrombus formation. Natural anticoagulants include: a. Tissue plasminogen activator (TPA) b. Antithrombin III c. Activated protein C d. Heparin cofactor II
Last Answer : Answer: b, c, d Just as thrombin generation is the key to coagulation, antithrombin III is the most central anticoagulant proteins. This glycoprotein binds to thrombin, preventing its removal of ... in the body. Therefore, TPA is part of the fibrinolytic system rather than a natural anticoagulant
Description : Fibrinolytic therapy is based on activation of plasminogen, the inactive proteolytic enzyme of plasma that binds to fibrin during the formation of thrombosis. Activation of plasminogen to plasmin results ... TPA all exceed 30 minutes d. Streptokinase is significantly cheaper than urokinase or TPA
Last Answer : Answer: a, b, d Streptokinase is a bacterial protein produced by group C b-hemolytic streptococci. It is therefore antigenic in humans and can be associated with allergic reaction in ... one agent over the other. Streptokinase however, is markedly less expensive than either urokinase or TPA
Description : Nucleotide found free in the cells is: (a) CAMP (b) AMP (c) ADP (d) ATP
Last Answer : Ans. ((d))
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 : Regulation of haem synthesis occurs by (A) Covalent modification (B) Repression - derepression (C) Induction (D) Allosteric regulation
Description : Glucose-6-phosphatase and PEP carboxy kinase are regulated by (A) Covalent modification (B) Allosteric regulation (C) Induction and repression (D) All of these
Description : Allosteric enzymes regulate the formation of products by (A) Feedback inhibition (B) Non-competitive inhibition (C) Competitive inhibition (D) Repression-derepression
Description : Acetyl CoA carboxylase regulates fatty acid synthesis by which of the following mechanism? (A) Allosteric regulation (B) Covalent modification (C) Induction and repression (D) All of these
Description : Pyruvate carboxylase is regulated by (A) Induction (B) Repression (C) Allosteric regulation(D) All of these
Last Answer : D