Description : Salvage of purine bases is regulated by (A) Adenosine phosphoribosyl transferase (B) Hypoxanthine guanine phosphoribosyl transferase (C) Availability of PRPP (D) None of these
Last Answer : Answer : C
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
Last Answer : Answer : B
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 : Answer : A
Description : Free purine bases which can be salvaged are (A) Adenine and guanine (B) Adenine and hypoxanthine (C) Guanine and hypoxanthine (D) Adenine, guanine and hypoxanthine
Last Answer : Answer : D
Description : All the following statements about primary gout are true except (A) Its inheritance is X-linked recessive (B) It can be due to increased activity of PRPP synthetase (C) It can be ... activity of hypoxanthine guanine phosphoribosyl transferase (D) De novo synthesis of purines is increased in it
Description : An alternate substrate for orotate phosphoribosyl transferase is (A) Allopurinol (B) Xanthine (C) Hypoxanthine (D) Adenine
Description : Conversion of inosine monophosphate to xanthine monophosphate is catalysed by (A) IMP dehydrogenase (B) Formyl transferase (C) Xanthine-guanine phosphoribosyl transferase (D) Adenine phosphoribosyl transferase
Description : Which two of the following four bases in DNA are purine bases? a) adenine b) thymine c) cytosine d) guanine
Last Answer : ANSWER: A and D -- ADENINE and GUANINE
Description : Complete absence of hypoxanthine guanine phospharibosyl transferase causes (A) Primary gout (B) Immunodeficiency (C) Uric acid stones (D) Lesh-Nyhan syndrome
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
Description : Nitrosamine can deaminate (A) Cytosine to form uracil (B) Adenine to form xanthine (C) Guanine to form hypoxanthine (D) All of these
Description : The first reaction unique to purine nucleotide synthesis is catalysed by (A) PRPP synthetase (B) PRPP glutamyl amido transferase (C) Phosphoribosyl glycinamide synthetase (D) Formyl transferase
Description : In RNA molecule guanine content does not necessarily equal its cytosine content nor does its adenine content necessarily equal its uracil content since it is a (A) Single strand molecule ( ... stranded molecule (C) Double stranded helical molecule (D) Polymer of purine and pyrimidine ribonucleotides
Description : The available PRPP is used preferentially for (A) De novo synthesis of purine nucleotides (B) De novo synthesis of pyrimidine nucleotides (C) Salvage of purine bases (D) Salvage of pyrimidine bases
Description : Orotic aciduria type II reflects the deficiency of the enzyme: (A) Orotate phosphoribosyl transferase (B) Orotidylate decarboxylase (C) Dihydroorotase (D) Dihydroorotate dehydrogenase
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 : 5-Phosphoribosyl-1-pyrophosphate is required for the synthesis of (A) Purine nucleotides (B) Pyrimidine nucleotides (C) Both (A) and (B) (D) None of these
Description : A common substrate of HGPRTase, APRTase and PRPP glutamyl amidotransferase is (A) Ribose 5 phosphate (B) Phosphoribosyl pyrophosphate (C) Hypoxanthine (D) Adenosine
Description : An enzyme which acts as allosteric regulator and sensitive to both phosphate concentration and to the purine nucleotides is (A) PRPP synthetase (B) PRPP glutamyl midotransferase (C) HGPR Tase (D) Formyl transferase
Description : Which of the following statement(s) is/are true concerning DNA? a. DNA is contained only in the nucleus of the cell b. DNA strands are encoded by the sequence of four bases-adenine, guanine, cytosine ... DNA is the intron, a sequence of three bases d. There are an infinite number of possible codons
Last Answer : Answer: a The genetic blueprint of an organism is carried in the nucleus of every cell, encoded by the sequence of four bases-adenine, guanine, cytosine and thymine, which together make up ... codons. Sixty-one of these code for amino acids and three are termination signals called stop codons
Description : With regard to DNA molecules: a. they contain adenine, cytosine, guanine and uracil bases b. they can be detected with Western blotting c. they can be detected with Southern blotting d. they are denatured at temperature of 1000C
Last Answer : they can be detected with Southern blotting
Description : Which one of the following pairs of nitrogenous bases of nucleic acids, is wrongly matched with the category mentioned against it? (a) Guanine, Adenine - Purines (b) Adenine, Thymine - Purines (c) Thymine, Uracil - Pyrimidines (d) Uracil, Cytosine - Pyrimidines
Last Answer : (b) Adenine, Thymine - Purines
Description : Which two of the following four bases in DNA are pyrimidine (pron: pie-rim-eh-den) bases? a) cytosine b) thymine c) adenine d) guanine (pron: gwa - neen)
Last Answer : ANSWER: A and B -- CYTOSINE and THYMINE
Description : Leishmania donovani is susceptible to certain antifungal drugs because both fungi and Leishmania: A. Utilise purine salvage pathway B. Utilise similar glycolytic mechanisms C. Have similar topoisomerase II enzyme D. Have ergosterol in their cell membranes
Last Answer : D. Have ergosterol in their cell membranes
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 : 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 : The major determinant of the overall rate of denovo purine nucleotide biosynthesis is the concentration of (A) 5-phosphoribosyl 1-pyrophosphate (B) 5-phospho β-D-ribosylamine (C) Glycinamide ribosyl-5-phosphate (D) Formylglycinamide ribosyl-5-phosphate
Description : The key substance in the synthesis of purine, phosphoribosyl pyrophosphate is formed by (A) α-D-ribose 5-phosphate (B) 5-phospho β-D-ribosylamine (C) D-ribose (D) Deoxyribose
Description : The end product of purine catabolism in man is (A) Inosine (B) Hypoxanthine (C) Xanthine (D) Uric acid
Description : Nucleotides required for the synthesis of nucleic acids can be obtained from (A) Dietary nucleic acids and nucleotides (B) De novo synthesis (C) Salvage of pre-existing bases and nucleosides (D) De novo synthesis and salvage
Description : Adenosine kinase can salvage (A) Adenosine (B) Adenosine and deoxyadenosine (C) Adenosine and guanosine (D) Adenine and adenosine
Description : Deoxycytidine kinase can salvage (A) Adenosine (B) Adenosine and deoxyadenosine (C) Adenosine and guanosine (D) Adenine and adenosine
Description : In RNA, apart from ribose and phosphate, all following are present except (A) Adenine (B) Guanine (C) Thymine (D) Cytosine
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 : Substitution of an adenine base by guanine in DNA is known as (A) Transposition (B) Transition (C) Transversion (D) Frameshift mutation
Description : Exposure of DNA to ultraviolet radiation can lead to the formation of (A) Adenine dimers (B) Guanine dimers (C) Thymine dimers (D) Uracil dimers
Description : In RNA, the complementary base of adenine is (A) Cytosine (B) Guanine (C) Thymine (D) Uracil
Description : The complementary base of adenine in RNA is (A) Thymine (B) Cystosine (C) Guanine (D) Uracil
Description : In DNA, three hydrogen bonds are formed between (A) Adenine and guanine (B) Adenine and thymine (C) Guanine and cytosine (D) Thymine and cytosine
Description : In DNA, the complementary base of adenine is (A) Guanine (B) Cytosine (C) Uracil (D) Thymine
Description : The most likely lethal mutation is (A) Substitution of adenine for cytosine (B) Insertion of one nucleotide (C) Deletion of three nucleotides (D) Substitution of cytosine for guanine
Description : An increased melting temperature of duplex DNA results from a high content of (A) Adenine + Guanine (B) Thymine + Cytosine (C) Cytosine + Guanine (D) Cytosine + Adenine
Description : In DNA molecule (A) Guanine content does not equal cytosine content (B) Adenine content does not equal thymine content (C) Adenine content equals uracil content (D) Guanine content equals cytosine content
Description : In RNA molecule (A) Guanine content equals cytosine (B) Adenine content equals uracil (C) Adenine content equals guanine (D) Guanine content does not necessarily equal its cytosine content.
Description : The nucleic acid base found in mRNA but not in DNA is (A) Adenine (B) Cytosine (C) Guanine (D) Uracil
Description : Coenzyme A contains a nitrogenous base which is (A) Adenine (B) Guanine (C) Choline (D) Ethanolamine
Description : All of the following enzymes are unique to purine nucleotide synthesis except (A) PRPP synthetase (B) PRPP glutamyl amido transferase (C) Adenylosuccinate synthetase (D) IMP dehydrogenase
Description : In the pathway of de novo synthesis of purine nucleotides, all the following are allosteric enzymes except (A) PRPP glutamyl amido transferase (B) Adenylosuccinate synthetase (C) IMP dehydrogenase (D) Adenylosuccinase
Description : Adenine is (A) 6-Amino purine (B) 2-Amino-6-oxypurine (C) 2-Oxy-4-aminopyrimidine (D) 2, 4-Dioxypyrimidine
Description : Following nucleotides are called purines a. adenine b. guanine c. both d. none
Last Answer : both