Description : A drug which prevents uric acid synthesis by inhibiting the enzyme xanthine oxidase is (A) Aspirin (B) Allopurinol (C) Colchicine (D) Probenecid
Last Answer : B
Last Answer : (B) Allopurinol
Description : In humans purine are catabolised to uric acid due to lack of the enzyme: (A) Urease (B) Uricase (C) Xanthine oxidase (D) Guanase
Last Answer : Answer : B
Description : Schardinger’s enzyme is (A) Lactate dehydrogenase (B) Xanthine dehydrogenase (C) Uric oxidase (D) L amino acid dehydrogenase
Description : All of the following statements about allopurinol are true except (A) It is a structural analogue of uric acid (B) It can prevent uric acid stones in the kidneys (C) It increases the urinary excretion of xanthine and hypoxanthine (D) It is a competitive inhibitor of xanthine oxidase
Last Answer : Answer : A
Description : Which of the following statements are true of oxidants? A. In addition to their pathophysiologic roles in inflammation, injury, and infection, oxidants also have physiologic roles. B. Oxidants may ... involved the catalytic production of superoxide anion (O 2 ) by the enzyme xanthine oxidase.
Last Answer : Answer: ABCD DISCUSSION: Oxidants are reactive oxygen metabolites that have both physiologic and pathophysiologic roles. As potent oxidizing agents, oxidants are involved in cytochrome P ... leukocyte infiltration and activation, causing further tissue damage by the release of cytotoxic proteases
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 : An enzyme which uses hydrogen acceptor as substrate is (A) Xanthine oxidase (B) Aldehyde oxidase (C) Catalase (D) Tryptophan oxygenase
Last Answer : Answer : C
Description : Which of the following does not give benzoic acid on hydrolysis? (1) phenyl cyanide (2) benzoyl chloride (3) benzyl chloride (4) methyl benzoate
Last Answer : (3) benzyl chloride Explanation: Hydrolysis is any chemical reaction in which a molecule of water ruptures one or more chemical bonds.
Description : Which of the following esters produces butyric acid and phenol on hydrolysis? (a) Phenyl butyrate (b) Butyl benzoate (c) Benzyl propionate (d) Phenyl propionate
Last Answer : Phenyl butyrate
Description : Streptomycin prevents synthesis of polypeptide by (A) Inhibiting initiation process (B) Releasing premature polypeptide (C) Inhibiting peptidyl transferase activity (D) Inhibiting translocation
Description : Albinism is a congenital disorder resulting from the lack of which enzyme? (a) Tyrosinase (b) Xanthine oxidase (c) Catalase (d) Fructokinase
Last Answer : (a) Tyrosinase
Description : A molybdenum containing oxidase is (A) Cytochrome oxidase (B) Xanthine oxidase (C) Glucose oxidase (D) L-Amino acid oxidase
Description : Non steroidal anti inflammatory drugs, such as aspirin act by inhibiting the activity of the enzyme: (A) Lipoxygenase (B) Cyclooxygenase (C) Phospholipase A2 (D) Lipoprotein lipase
Description : The end product of purine catabolism in man is (A) Inosine (B) Hypoxanthine (C) Xanthine (D) Uric acid
Last Answer : Answer : D
Description : The correct sequence of the reactions of catabolism of adenosine to uric acid is (A) Adenosine→hypoxanthine→xanthine→uric acid (B) Adenosine→xanthine→inosine→uric acid (C) Adenosine→inosine→hypoxanthine→ xanthine uric acid (D) Adenosine→xanthine→inosine→hypoxanthine uric acid
Description : In humans end product of purine catabolism is (A) Uric acid (B) Urea (C) Allantoin (D) Xanthine
Description : Xanthuric acid is an abnormal metabolite of (A) Xanthine (B) Uric acid (C) Tyrosine (D) Tryptophan
Description : The action of aspirin that results in its greater efficacy as an antithrombotic (anti-platelet) drug is its ability to (a) Inhibit lipoxygenase as well as cyclooxygenase (b) Selectively inhibit ... I (c) Inhibit leukocyte migration (d) Promote uric acid excretion (e) Acetylate cyclooxygenase
Last Answer : Ans: E
Description : Choose the correct statement about paracetamol: A. It increases uric acid excretion B. It is the most common drug implicated in causing analgesic nephropathy C. In equianalgesic doses it is safer than aspirin D. It stimulates cellular metabolism
Last Answer : C. In equianalgesic doses it is safer than aspirin
Description : 5 HIAA test is negative if patient is taking (A) Aspirin (B) Colchicine (C) Phenothiazone (D) Methotrexate
Description : Hypouricaemia can occur in (A) Xanthine oxidase deficiency (B) Psoriasis (C) Leukaemia (D) None of these
Description : Mammals other than higher primates do not suffer from gout because they (A) Lack xanthine oxidase (B) Lack adenosine deaminase (C) Lack purine nucleoside phosphorylase (D) Possess uricase
Description : Enzymic deficiency in β-aminoisobutyric aciduria is (A) Adenosine deaminase (B) Xanthine oxidase (C) Orotidylate decarboxylase (D) Transaminase
Description : An autosomal recessive disorder, xanthinuria is due to deficiency of the enzymes: (A) Adenosine deaminase (B) Xanthine oxidase (C) HGPRTase (D) Transaminase
Description : Molybdenum is a cofactor for (A) Xanthine oxidase (B) Aldehyde oxidase (C) Sulphite oxidase (D) All of these
Description : Iron is present in all the following except (A) Peroxidase (B) Xanthine oxidase (C) Aconitase (D) Fumarase
Description : A copper containing oxidase is (A) Cytochrome oxidase (B) Flavin mononucleotide (C) Flavin adenine dinucleotide (D) Xanthine oxidase
Description : Physostigmine is a competitive inhibitor of (A) Xanthine oxidase (B) Cholinesterase (C) Carbonic anhydrase (D) Monoamine oxidase
Description : Insulin degradation of disulfide bond formation is effected by (A) Pyruvate dehydrogenase (B) Xylitol reductase (C) Gutathione reductase (D) Xanthine oxidase
Description : Aspirin prolongs bleeding time by inhibiting the synthesis of: A. Clotting factors in liver B. Prostacyclin in vascular endothelium C. Cyclic AMP in platelets D. Thromboxane A2 in platelets
Last Answer : D. Thromboxane A2 in platelets
Description : Low doses of aspirin prolong bleeding time by selectively inhibiting synthesis of the following mediator in the platelets: A. Thromboxane A2 B. 5-Hydroxytryptamine C. Platelet activating factor D. Prostacyclin
Last Answer : A. Thromboxane
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 : Which of the following compounds is aspirin (a) Methyl salicylate (b) Salicylic acid (c) Phenyl salicylate (d) Acetylsalicylic acid
Last Answer : Acetylsalicylic acid
Description : Aspirin is (1) Methoxy benzoic acid (2) Methyl Salicilate (3) Acetyl Salicilic acid (4) Phenyl Salicilate
Last Answer : Acetyl Salicilic acid
Description : Allopurinol lowers the plasma concentration of: A. Hypoxanthine B. Xanthine C. Uric acid D. All of the above
Last Answer : C. Uric acid
Description : A patient who has been taking quantities of aspirin might show increased post operative bleeding because aspirin inhibits:** A. Synthesis of thromboxane A2 and prevents platelet aggregation B. ... network E. Increase the absorption of vitamin K and prevents synthesis of blood clotting factors
Last Answer : A. Synthesis of thromboxane A2 and prevents platelet aggregation
Description : Which of the following is a disease modifying antirheumatic drug whose active metabolite inhibits the enzyme dihydro-orotate dehydrogenase: A. Leflunomide B. Nimesulide C. Sulfasalazine D. Colchicine
Last Answer : A. Leflunomide
Description : Isoniazid has a very narrow drug spectrum as the active form of the drug specifically interferes with cell wall synthesis in _____ by inhibiting the production of mycolic acid in the cell wall. a. Staphylococcus b. Streptococcus c. Enterococcus d. Mycobacterium
Last Answer : d. Mycobacterium
Description : Which one of the following drugs is not useful in dysmenorrhea? (a) Aspirin (b) Colchicine (c) Ibuprofen (d) Rofecoxib (e) Naproxen
Last Answer : Ans: B
Description : Which of the following enzymes is ultimately responsible for the production of prostaglandins associated with inflammatory reactions? (a) Phospholipase (b) Lipoxygenase (c) Cyclooxygenase-I (d) Cyclooxygenase II (e) Xanthine oxidase
Last Answer : Ans: D
Description : Thioguanine differs from mercaptopurine in that: A. It is not metabolized by xanthine oxidase B. It does not cause hyperuricemia C. Its dose need not be reduced when allopurinol is given concurrently D. Both ‘A’ and ‘C’ are correc
Last Answer : D. Both ‘A’ and ‘C’ are correct
Description : Choose the correct statement about allopurinol: A. It is a purine antimetabolite with antineoplastic activity B. It is a competitive inhibitor of xanthine oxidase C. It is inactive itself ... D. Both allopurinol as well as its metabolite alloxanthine are noncompetitive inhibitors of xanthine oxidase
Last Answer : B. It is a competitive inhibitor of xanthine oxidase
Description : Colchicine is an inhibitory chemical, which (a) stops the functioning of centriole (b) prevents attaching of centromeres with rays (c) prevents the spindle formation in mitosis (d) prevents the formation of equatorial plane.
Last Answer : (c) prevents the spindle formation in mitosis
Description : Diazoxide is an effective hypotensive, but is not used in the long-term treatment of hypertension because: A. It impairs glucose tolerance by inhibiting insulin release B. It inhibits uric acid ... causes marked Na+ and water retention leading to development of tolerance D. All of the above
Last Answer : D. All of the above
Description : Regulator gene controls chemical synthesis (Operon concept) by (a) Inhibiting transcription of mRNA (b) Inhibiting enzymes (c) Inhibiting passage of mRNA (d) Inhibiting substrate enzyme reaction
Last Answer : Ans. ((a))
Description : The polyene antibiotics act by: A. Inhibiting fungal cytochrome P450 enzyme B. Binding to ergosterol and creating micropores in fungal cell membrane C. Inhibiting fungal DNA synthesis D. Disorienting microtubules in fungal cells
Last Answer : B. Binding to ergosterol and creating micropores in fungal cell membrane
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 : An enzyme involved in catabolism of catecholamines is (A) Dopa decarboxylase (B) Aromatic amino acid decarboxylase (C) Monoamine oxidase (D) Catechol oxidas
Description : Albinism is due to deficiency of the enzyme: (A) Phenylalanine hydroxylase (B) Tyrosinase (C) p-Hydroxyphenylpyruvic acid oxidase (D) Tyrosine dehydrogenase