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
Last Answer : Answer : D
Description : A drug which prevents uric acid synthesis by inhibiting the enzyme Xanthine oxidase is (A) Aspirin (B) Allopurinal (C) Colchicine (D) Phenyl benzoate
Last Answer : Answer : B
Description : Schardinger’s enzyme is (A) Lactate dehydrogenase (B) Xanthine dehydrogenase (C) Uric oxidase (D) L amino acid dehydrogenase
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
Description : In humans end product of purine catabolism is (A) Uric acid (B) Urea (C) Allantoin (D) Xanthine
Last Answer : Answer : A
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
Last Answer : (B) Allopurinol
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
Description : The end product of purine catabolism in man is (A) Inosine (B) Hypoxanthine (C) Xanthine (D) Uric acid
Description : The enzyme common to catabolism of all the purines is (A) Adenosine deaminase (B) Purine nucleoside phosphorylase (C) Guanase (D) None of these
Description : The enzyme using some other substance, not oxygen as hydrogen acceptor is (A) Tyrosinase (B) Succinate dehydrogenase (C) Uricase (D) Cytochrome oxidase
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 : 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 : 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 : An autosomal recessive disorder, xanthinuria is due to deficiency of the enzymes: (A) Adenosine deaminase (B) Xanthine oxidase (C) HGPRTase (D) Transaminase
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 : A molybdenum containing oxidase is (A) Cytochrome oxidase (B) Xanthine oxidase (C) Glucose oxidase (D) L-Amino acid oxidase
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 : Xanthuric acid is an abnormal metabolite of (A) Xanthine (B) Uric acid (C) Tyrosine (D) Tryptophan
Description : Hypouricaemia can occur in (A) Xanthine oxidase deficiency (B) Psoriasis (C) Leukaemia (D) None of these
Description : Enzymic deficiency in β-aminoisobutyric aciduria is (A) Adenosine deaminase (B) Xanthine oxidase (C) Orotidylate decarboxylase (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 : 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 : Uric acid is the end product of purine as well as protein catabolism in (A) Man (B) Fish (C) Birds (D) None of these
Description : A 73 year old male presented with an acute attack of gout in his left knee. What is the most likely underlying metabolic cause? 1) decreased renal excretion of uric acid 2) endogenous overproduction of uric acid 3) excessive dietary purine intake 4) lactic acidosis 5) starvation
Last Answer : Answers-1 The aetiology of gout can broadly be divided into cases where there is underexcretion of urate via the kidney (90%) or endogenous overproduction of uric acid (10%) although in practical ... diuretic use. Excessive dietary intake of purines is unlikely to be the main cause in this case.
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 : Albinism is due to deficiency of the enzyme: (A) Phenylalanine hydroxylase (B) Tyrosinase (C) p-Hydroxyphenylpyruvic acid oxidase (D) Tyrosine dehydrogenase
Description : Fabry’s disease is due to the deficiency of the enzyme: (A) Ceramide trihexosidase (B) Galactocerebrosidase (C) Phytanic acid oxidase (D) Sphingomyelinase
Description : An enzyme common to de novo synthesis of pyrimidine nucleotides and urea is (A) Urease (B) Carbamoyl phosphate synthetase (C) Aspartate transcarbamoylase (D) Argininosuccinase
Description : The first enzyme isolated, purified and crystallied from Jack bean (Canavalia) by summer in 1926 was (A) Urease (B) Insulin (C) Ribonuclease (D) Zymase
Description : Urea is produced physiologically by the action of the enzyme: (A) Urease (B) Glutaminase (C) Arginase (D) None of these
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 : In plants, enzyme responsible for the synthesis of the malic acid is : (A) Rubisco (B) PEP carboxylase (C)Kinase (D) Urease
Last Answer : (A) Rubisco
Description : Assertion: Uric acid is produced by the metabolism of purine and pyrimidine. Reason: Uric acid has high toxicity and is soluble in water.
Last Answer : Assertion: Uric acid is produced by the metabolism of purine and pyrimidine. Reason: Uric acid has ... D. If both Assertion and Reason are false
Description : All of the following statements about proline are true except (A) It is an imino acid (B) It can be synthesized from glutamate (C) It can be catabolised to glutamate (D) Free proline can be hydroxylated to hydroxyproline
Description : Refsum’s disease is due to deficiency of the enzyme: (A) Pytantate-α-oxidase (B) Glucocerebrosidase (C) Galactocerebrosidase (D) Ceramide trihexosidase
Description : Alkaptonuria occurs due to deficiency of the enzyme: (A) Maleylacetoacetate isomerase (B) Homogentisate oxidase (C) p-Hydroxyphenylpyruvate hydroxylase (D) Fumarylacetoacetate hydrolase
Description : An enzyme involved in catabolism of catecholamines is (A) Dopa decarboxylase (B) Aromatic amino acid decarboxylase (C) Monoamine oxidase (D) Catechol oxidas
Description : J. B. Sumner isolated first enzyme from Jackbeans as- (1) amylase (2) trypsin (3) urease (4) renin
Last Answer : (3) urease Explanation: James Batcheller Sumner (November 19, 1887 – August 12, 1955) was an American chemist. He discovered that enzymes can be crystallized.
Description : Destruction of which of the following enzyme causes cyanide poisoning (a) Zymogen (b) Cytochrome enzyme (c) Urease (d) None of these
Last Answer : (b) Cytochrome enzyme
Description : All are true about lesch-nyhan syndrome except (A) Produces self-mutilation (B) Genetic deficiency of the enzyme (C) Elevated levels of uric acid in blood (D) Inheritance is autosomal recessive
Description : In humans, the principal metabolic product of pyrimidines is (A) Uric acid (B) Allantoin (C) Hypoxanthine (D) β-alanine
Description : In humans, the principal break down product of purines is (A) NH3 (B) Allantin (C) Alanine (D) Uric acid
Description : In humans, NH3 is detoxified in liver as (A) Creatinine (B) Uric acid (C) Urea (D) Uronic acid
Description : Dietary purines are catabolised in (A) Liver (B) Kidneys (C) Intesitnal mucosa (D) All of these