Description : Which one of the following contributes nitrogen atoms to both purine and pyrimidine rings? (A) Aspartate (B) Carbanoyl phosphate (C) Carbondioxide (D) Tetrahydrofolate
Last Answer : Answer : A
Description : Pyrimidine biosynthesis begins with the formation from glutamine, ATP and CO2, of (A) Carbamoyl aspartate (B) Orotate (C) Carbamoyl phosphate (D) Dihydroorotate
Last Answer : Answer : C
Description : The two nitrogen of the pyrimidine ring are contributed by (A) Ammonia and glycine (B) Asparate and carbamoyl phosphate (C) Glutamine and ammonia (D) Aspartate and ammonia
Last Answer : Answer : B
Description : The carbon atoms of pyrimidine nucleus are provided by (A) Glycine and aspartate (B) CO2 and aspartate (C) CO2 and glutamate (D) CO2 and glutamine
Description : The nitrogen atoms of pyrimidine nucleus are provided by (A) Glutamate (B) Glutamate and aspartate (C) Glutamine (D) Glutamine and aspartate
Last Answer : Answer : D
Description : The nitrogen atoms for de novo synthesis of purine nucleotides are provided by (A) Aspartate and glutamate (B) Aspartate and glycine (C) Aspartate, glutamine and glycine (D) Aspartate, glutamate and glycine
Description : De novo synthesis of pyrimidine nucleotides is regulated by (A) Carbamoyl phosphate synthetase (B) Aspartate transcarbamoylase (C) Both (A) and (B) (D) None of these
Description : Cytosolic carbamoyl phosphate synthetase is activated by (A) Glutamine (B) PRPP (C) ATP (D) Aspartate
Description : All the enzymes required for de novo synthesis of pyrimidine nucleotides are cytosolic except (A) Carbamoyl phosphate synthetase (B) Aspartate transcarbamoylase (C) Dihydro-orotase (D) Dihydro-orotate dehydrogenase
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 carbon atom at position 2 of pyrimidine nucleus is contributed by (A) CO2 (B) Glycine (C) Aspartate (D) Glutamine
Description : In the purine nucleus, carbon 6 is contributed by (A) Glycine (B) CO2 (C) Aspartate (D) Glutamine
Description : Aspartate contributes the following carbon atoms of the pyrimidine nucelus: (A) C2 and C4 (B) C5 and C6 (C) C2, C4 and C6 (D) C4, C5 and C6
Description : Nitrogen at position 3 of pyrimidine nucleus comes from (A) Glutamine (B) Glutamate (C) Glycine (D) Aspartate
Description : Nitrogen at position 1 of pyrimidine nucleus comes from (A) Glutamine (B) Glutamate (C) Glycine (D) Aspartate
Description : The four nitrogen atoms of purines are derived from (A) Urea and NH3 (B) NH3, Glycine and Glutamate (C) NH3, Asparate and Glutamate (D) Aspartate, Glutamine and Glycine
Description : The 2 nitrogen atoms in urea are contributed by (A) Ammonia and glutamate (B) Glutamine and glutamate (C) Ammonia and aspartate (D) Ammonia and alanine
Description : Carbamoyl phosphate synthetase structure is marked by change in the presence of (A) N-Acetyl glutamate (B) N-Acetyl Aspartate (C) Neuraminic acid (D) Oxalate
Description : A key substance in the committed step of pyrimidines biosynthesis is (A) Ribose-5-phosphate (B) Carbamoyl phosphate (C) ATP (D) Glutamine
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 : A nucleotide is formed of (a) purine, pyrimidine and phosphate (b) purine, sugar and phosphate (c) nitrogen base, sugar and phosphate (d) pyrimidine, sugar and phosphate
Last Answer : (c) nitrogen base, sugar and phosphate
Description : Two nitrogen of the pyrimidines ring are obtained from (A) Glutamine and Carbamoyl-p (B) Asparate and Carbamoyl-p (C) Glutamate and NH3 (D) Glutamine and NH3
Description : Vitamin B12 has a complex ring structure (corrin ring) consisting of four (A) Purine rings (B) Pyrimidine rings (C) Pyrrole rings (D) Pteridine rings
Description : Intestinal nucleosidases act on nucleosides and produce (A) Purine base only (B) Phosphate only (C) Sugar only (D) Purine or pyrimidine bases and sugars
Description : In purine biosynthesis carbon atoms at 4 and 5 position and N at 7 position are contributed by (A) Glycine (B) Glutamine (C) Alanine (D) Threonine
Description : For de novo synthesis of purine nucleotides, aspartate provides (A) Nitrogen 1 (B) Nitrogen 3 (C) Nitrogen 7 (D) Nitrogen 9
Description : In purine nucleus nitrogen atom at 1 position is derived from (A) Aspartate (B) Glutamate (C) Glycine (D) Alanine
Description : N10-formyl and N5N10-methenyl tetrahydrofolate contributes purine carbon atoms at position (A) 4 and 6 (B) 4 and 5 (C) 5 and 6 (D) 2 and 8
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
Description : In brain, the major metabolism for removal of ammonia is the formation of (A) Glutamate (B) Aspartate (C) Asparagine (D) Glutamine
Description : The amino acid that undergoes oxidative deamination at significant rate is (A) Alanine (B) Aspartate (C) Glutamate (D) Glutamine
Description : Two nitrogen atoms of Urea in the urea cycle come from (A) NH3 (B) One from NH3 and one from aspartate (C) One from NH3 and one from glutamate (D) One from NH3 and one from alanine
Description : The enzyme aspartate transcarbamoylase of pyrimidine biosynthesis is inhibited by (A) ATP (B) ADP (C) AMP (D) CTP
Description : An enzyme of pyrimidine nucleotide biosynthesis sensitive to allosteric regulation is (A) Aspartate transcarbamoylase (B) Dihydroorotase (C) Dihydroorotate dehydrogenase (D) Orotidylic acid decarboxylase
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 : Cytosolic and mitochondrial carbamoyl phosphate synthetase have the following similarity: (A) Both use ammonia as a substance (B) Both provide carbamoyl phosphate for urea synthesis (C) Both require N-acetylglutamate as an activator (D) Both are allosteric enzymes
Description : Carbamoyl phosphate required for urea synthesis is formed in (A) Cytosol (B) Mitochondria (C) Both (A) and (B) (D) None of these
Description : For de novo synthesis of purine nucleotides, glycine provides (A) One nitrogen atom (B) One nitrogen and one carbon atom (C) Two carbon atoms (D) One nitrogen and two carbon atoms
Description : Which one of the following causes frame shift mutation? (A) Transition (B) Transversion (C) Deletion (D) Substitution of purine to pyrimidine
Description : In DNA, genetic information is located in (A) Purine bases (B) Pyrimidine bases (C) Purine and pyrimidine bases (D) sugar
Description : The structural stability of the double helix of DNA is as cribbed largely to (A) Hydrogen bonding between adjacent purine bases (B) Hydrophobic bonding between staked purine and ... Hydrogen bonding between adjacent pyrimidine bases (E) Hydrogen bonding between purine and pyrimidine bases
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 : Ultraviolet light can damage a DNA strand causing (A) Two adjacent purine residue to form a covalently bounded dimer (B) Two adjacent pyrimidine residues to form covalently bonded dimer (C) Disruption of phosphodiesterase linkage (D) Disruption of non-covalent linkage
Description : Genetic code is (A) Collection of codon (B) Collection of amino acids (C) Collection of purine nucleotide (D) Collection of pyrimidine nucleotide
Description : Gout is a metabolic disorder of catabolism of (A) Pyrimidine (B) Purine (C) Alanine (D) Phenylalanine
Description : Pyrimidine and purine nucleoside biosynthesis share a common precursor: (A) PRPP (B) Glycine (C) Fumarate (D) Alanine
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 : A nucleotide consists of (A) A nitrogenous base like choline (B) Purine + pyrimidine base + sugar + phosphorous (C) Purine or pyrimidine base + sugar (D) Purine or pyrimidine base + phosphorous
Description : A nucleoside consists of (A) Nitrogenous base (B) Purine or pyrimidine base + sugar (C) Purine or pyrimidine base + phosphorous (D) Purine + pyrimidine base + sugar + phosphorous