Description : Hybridoma cells are selected by culturing them in a medium containing (A) Adenine, guanine, cytosine and thymine (B) Adenine, guanine, cytosine and uracil (C) Hypoxanthine, aminopterin and thymine (D) Hypoxanthine, aminopterin and thymidine
Last Answer : Answer : D
Description : The following cannot be salvaged in human beings: (A) Cytidine (B) Deoxycytidine (C) Cytosine (D) Thymidine
Last Answer : Answer : C
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 : Increased urinary excretion of orotic acid can occur in deficiency of (A) Orotate phosphoribosyl transferase (B) OMP decarboxylase (C) Mitochondrial ornithine transcarbamoylase (D) Any of the above
Description : All of the following occur in orotic aciduria except (A) Increased synthesis of pyrimidine nucleotides (B) Increased excretion of orotic acid in urine (C) Decreased synthesis of cytidine triphosphate (D) Retardation of growth
Last Answer : Answer : A
Description : Orotic aciduria can be controlled by (A) Oral administration of orotic acid (B) Decreasing the dietary intake of orotic acid (C) Decreasing the dietary intake of pyrimidines (D) Oral administration of uridine
Description : During de novo synthesis of pyrimidine nucleotides, the first ring compound to be formed is (A) Carbamoyl aspartic acid (B) Dihydro-orotic acid (C) Orotic acid (D) Orotidine monophosphate
Last Answer : Answer : B
Description : A cofactor in the conversion of dihydroorotate to orotic acid, catalysed by the enzyme dihydroorotate dehydrogenase is (A) FAD (B) FMN (C) NAD (D) NADP
Description : Conversion of deoxyuridine monophosphate to thymidine monophosphate is catalysed by the enzyme: (A) Ribonucleotide reductase (B) Thymidylate synthetase (C) CTP synthetase (D) Orotidylic acid decarboxylase
Description : Both Acyl carrier protein (ACP) of fatty acid synthetase and coenzyme (CoA) are (A) Contain reactive phosphorylated (B) Contain thymidine (C) Contain phosphopantetheine reactive groups (D) Contain cystine reactive groups
Description : Orotic aciduria type II reflects the deficiency of the enzyme: (A) Orotate phosphoribosyl transferase (B) Orotidylate decarboxylase (C) Dihydroorotase (D) Dihydroorotate dehydrogenase
Description : Orotic aciduria type I reflects the deficiency of enzymes: (A) Orotate phosphoribosyl transferase and orotidylate decarboxylase (B) Dihydroorotate dehydrogenase (C) Dihydroorotase (D) Carbamoyl phosphate synthetase
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 : 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 : In tRNA molecule D arm is named for the presence of the base: (A) Uridine (B) Pseudouridine (C) Dihydrouridine (D) Thymidine
Description : That sulfonamides act by inhibiting folate synthesis in bacteria is supported by the following findings except: A. Paraaminobenzoic acid antagonises the action of sulfonamides B. Methionine antagonises ... . Bacteria that utilise folic acid taken up from the medium are insensitive to sulfonamides
Last Answer : B. Methionine antagonises the action of sulfonamides
Description : Cholesterol is the precursor for the biosynthesis of (A) fatty acid (B) prostaglandins (C) bile acids (D) sphingmyelin
Description : Acid hydrolysis of ribonucleic acid would yield the following major products: (A) d- deoxyribose, cytosine, adenine (B) d-ribose, thymine, Guanine (C) d-ribose, cytosine, uracil, thymine (D) d-ribose, uracil, adenine, guanine, cytosine
Description : Which of the following statements about nucleic acid is most correct? (A) Both pentose nucleic acid and deoxypentose nucleic acid contain the same pyrimidines (B) Both pentose nucleic acid and deoxypentose ... (C) RNA contains cytosine and thymine (D) DNA and RNA are hydrolysed by weak alkali
Description : The nucleic acid base found in mRNA but not in DNA is (A) Adenine (B) Cytosine (C) Guanine (D) Uracil
Description : Organic compound of small molecular size is (A) Urea (B) Uric acid (C) Creatinine (D) Phosphates
Description : Which pathway is correct for catabolism of purines to form uric acid? (A) Guanylate→Adenylate→Xanthine→hypoxanthine→Uric acid (B) Guanylate→inosinate→Xanthine→hypoxanthine→Uric acid (C) Adenylate→Inosinate→Xanthine hypoxanthine→Uric acid (D) Adenylate→Inosinate→hypoxanthine Xanthine→Uric acid
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 most mammals, except primates, uric acid is metabolized by (A) Oxidation to allantoin (B) Reduction to NH3 (C) Hydrolysis to allantoin (D) Hydrolysis to NH3
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 : The probable metabolic defect in gents is (A) A defect in excretion of uric acid by kidney (B) An overproduction of pyrimidines (C) An overproduction of uric acid (D) Rise in calcium leading to deposition of calcium urate
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 : Uric acid is the catabolic end product of (A) Porphyrine (B) Purines (C) Pyrimidines (D) Pyridoxine
Description : When NH3 is perfused through a dog’s liver ______ is formed, while ______ is formed in the birds liver. (A) Urea, Uric acid (B) Urea, allantoin (C) Uric acid, creatinine (D) Uric acid, Urea
Description : All of the following can occur in LeschNyhan syndrome except (A) Gouty arthritis (B) Uric acid stones (C) Retarted growth (D) Self-mutiliating behaviour
Description : Complete absence of hypoxanthine guanine phospharibosyl transferase causes (A) Primary gout (B) Immunodeficiency (C) Uric acid stones (D) Lesh-Nyhan syndrome
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 : All of the following statements about primary gout are true except (A) Uric acid stones may be formed in kidneys (B) Arthritis of small joints occurs commonly (C) Urinary excretion of uric acid is decreased (D) It occurs predominantly in males
Description : All of the following statements about uric acid are true except (A) It can be formed from allantoin (B) Formation of uric acid stones in kidneys can be decreased by alkalinisation of urine (C) Uric acid begins to dissociate at pH above 5.8 (D) It is present in plasma mainly as monosodium urate
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 : 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 : Daily uric acid excretion in adult men is (A) 2–6 mg (B) 20–40 mg (C) 150–250 mg (D) 40–600 mg
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 : The end product of purine catabolism in man is (A) Inosine (B) Hypoxanthine (C) Xanthine (D) Uric acid
Description : The major catabolic product of pyrimidines in human is (A) β-Alanine (B) Urea (C) Uric acid (D) Guanine
Description : Gout is characterized by increased plasma levels of (A) Urea (B) Uric acid (C) Creatine (D) Creatinine
Description : In mammals other than higher primates uric acid is converted by (A) Oxidation to allantoin (B) Reduction to ammonia (C) Hydrolysis to ammonia (D) Hydrolysis to allantoin
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 : In humans end product of purine catabolism is (A) Uric acid (B) Urea (C) Allantoin (D) Xanthine
Description : Schardinger’s enzyme is (A) Lactate dehydrogenase (B) Xanthine dehydrogenase (C) Uric oxidase (D) L amino acid dehydrogenase
Description : Ammonia is excreted as ammonium salts during metabolic acidosis but the majority is excreted as (A) Phosphates (B) Creatine (C) Uric acid (D) Urea
Description : The end product of amino acid nitrogen metabolism in uricotelic organisms (reptiles and birds) is (A) Bilirubin (B) Urea (C) Uric acid (D) Biliverdin
Description : Amino acids provide the nitrogen for the synthesis of (A) The bases of the phospholipids (B) Uric acid (C) Glycolipids (D) Chondroitin sulphates
Description : The unwanted amino acids abstracted from the tissues are either used up by the tissue or in the liver converted into (A) Ammonia (B) Urea (C) Ammonium salts (D) Uric acid