Description : All of the following are iron-containing enzymes except (A) Carbonic anhydrase (B) Catalase (C) Peroxidase (D) Cytochrome oxidase
Last Answer : Answer : A
Description : The rate of citric acid cycle is controlled by the allosteric enzyme: (A) Aconitase (B) Fumarase (C) Fumarase (D) Malate dehydrogenase
Last Answer : Answer : C
Description : In TCA cycle, oxalosuccinate is converted to α-ketoglutarate by the enzyme: (A) Fumarase (B) Isocitrate dehydrogenase (C) Aconitase (D) Succinase
Last Answer : Answer : B
Description : An allosteric enzyme responsible for controlling the rate of T.C.A cycle is (A) Malate dehydrogenase (B) Isocitrate dehydrogenase (C) Fumarase (D) Aconitase
Last Answer : B
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 : Selenium is a constituent of the enzyme: (A) Glutathione peroxidase (B) Homogentisate oxidase (C) Tyrosine hydroxylase (D) Phenylalanin hydroxylase
Description : The pentose phosphate pathway protects erythrocytes against hemolysis by assisting the enzyme: (A) Superoxide dismutase (B) Catalase (C) Glutathionic peroxidase (D) Cytochrome oxidase ENZYMES 149
Description : Formation of melanin from tyrosine requires the action of (A) Dopa decarboxylation (B) Diamine oxidase (C) Peroxidase (D) Tyrosinase
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
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 : 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 : In humans purine are catabolised to uric acid due to lack of the enzyme: (A) Urease (B) Uricase (C) Xanthine oxidase (D) Guanase
Description : Molybdenum is a cofactor for (A) Xanthine oxidase (B) Aldehyde oxidase (C) Sulphite oxidase (D) All of these
Description : A copper containing oxidase is (A) Cytochrome oxidase (B) Flavin mononucleotide (C) Flavin adenine dinucleotide (D) Xanthine oxidase
Description : A molybdenum containing oxidase is (A) Cytochrome oxidase (B) Xanthine oxidase (C) Glucose oxidase (D) L-Amino acid oxidase
Description : Schardinger’s enzyme is (A) Lactate dehydrogenase (B) Xanthine dehydrogenase (C) Uric oxidase (D) L amino acid dehydrogenase
Description : Physostigmine is a competitive inhibitor of (A) Xanthine oxidase (B) Cholinesterase (C) Carbonic anhydrase (D) Monoamine oxidase
Description : An enzyme which uses hydrogen acceptor as substrate is (A) Xanthine oxidase (B) Aldehyde oxidase (C) Catalase (D) Tryptophan oxygenase
Description : Insulin degradation of disulfide bond formation is effected by (A) Pyruvate dehydrogenase (B) Xylitol reductase (C) Gutathione reductase (D) Xanthine oxidase
Description : A drug which prevents uric acid synthesis by inhibiting the enzyme xanthine oxidase is (A) Aspirin (B) Allopurinol (C) Colchicine (D) Probenecid
Description : Iron-pophyrin is present as prosthetic group in (A) Cytochromes (B) Catalases (C) Peroxidase (D) None of these
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 : 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 : 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 : 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
Last Answer : (B) Allopurinol
Description : The iron containing nonporphyrin is (A) Hemosiderin (B) Catalase (C) Cytochrome C (D) Peroxidase
Description : The enzymes present in the membrane of mitochondria are (A) Flavoproteins and cytochromes (B) Fumarase and lipase (C) Enolase and catalase (D) Hexokinase and zymase
Description : The nitrogenous base present in the RNA molecule is (A) Thymine (B) Uracil (C) Xanthine (D) Hypoxanthine
Description : All the following statements about ceruloplasmin are correct except (A) It is a copper-containing protein (B) It possesses oxidase activity (C) It is synthesised in intestinal mucosa (D) Its plasma level is decreased inWilson’s disease
Description : All the following statements about serotonin are true except (A) It causes vasolidatation (B) It causes bronchoconstriction (C) It is metabolized by monoamine oxidase (D) Its metabolite is 5-hydroxyindole acetic acid
Description : In citric acid cycle, GDP is phosphorylated by (A) Succinate dehydrogenase (B) Aconitase (C) Succinate thiokinase (D) Fumarse
Description : Acute hemolytic anemia in person’s sensitive to the Fava beans is due to the deficiency of the enzyme: (A) Pyruvate dehydrogenase (B) G-6-PD (C) Aconitase (D) Transketolase
Description : Fluoride inhibits ______ and arrests glycolysis. (A) Glyceraldehyde-3-phosphate dehydrogenase (B) Aconitase (C) Enolose (D) Succinate dehydrogenase
Last Answer : C
Description : Substrate level phosphorylation in TCA cycle is in step: (A) Isocitrate dehydrogenase (B) Malate dehydrogenase (C) Aconitase (D) Succinate thiokinase
Last Answer : D
Description : Citrate is converted to isocitrate by aconitase which contains (A) Ca++ (B) Fe++ (C) Zn++ (D) Mg++
Description : Calcium is required for the activation of the enzyme: (A) Isocitrate dehydrogenase (B) Fumarase (C) Succinate thiokinase (D) ATPase
Description : Among citric acid cycle enzymes, a flavoprotein is (A) Malate (B) Fumarase (C) Succinate dehrogenase (D) Isocitrate dehrogenase
Description : In pentose phosphate pathway, D-ribulose5-phosphate is converted to D-ribose-5- phosphate by the enzyme: (A) Fumarase (B) Ketoisomerase (C) G-6-PD (D) Epimerase
Description : An example of lyases is (A) Glutamine synthetase (B) Fumarase (C) Cholinesterase (D) Amylase
Description : An example of ligases is (A) Succinate thiokinase (B) Alanine racemase (C) Fumarase (D) Aldolase
Description : With the exception of glycine all amino acids found in protein are (A) Isocitrate dehydrogenase (B) Fumarase (C) Succinate thiokinase (D) ATPase
Description : Selenium is a constituent of (A) Glutathione reductase (B) Glutathione peroxidase (C) Catalase (D) Superoxide dismutase
Description : Hydrogen peroxide may be detoxified in the absence of an oxygen acceptor by (A) Peroxidase (B) Catalase (C) Both (A) and (B) (D) None of these
Description : Nitrosamine can deaminate (A) Cytosine to form uracil (B) Adenine to form xanthine (C) Guanine to form hypoxanthine (D) All of these
Description : An alternate substrate for orotate phosphoribosyl transferase is (A) Allopurinol (B) Xanthine (C) Hypoxanthine (D) Adenine