Description : Transfer of the carbamoyl moiety of carbamoyl phosphate to ornithine is catalysed by a liver mitochondrial enzyme: (A) Carbamoyl phosphate synthetase (B) Ornithine transcarbamoylase (C) N-acetyl glutamate synthetase (D) N-acetyl glutamate hydrolase
Last Answer : Answer : B
Description : The metabolite which sustains urea cycle is (A) Ornithine (B) Citrulline (C) Carbamoyl phosphate (D) n-acetyl glutamate
Last Answer : Answer : C
Description : Cytosolic carbamoyl phosphate synthetase is activated by (A) Glutamine (B) PRPP (C) ATP (D) Aspartate
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 : 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
Last Answer : Answer : D
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 : Hyperammonaemia type I results from congenital absence of (A) Glutamate dehydrogenase (B) Carbamoyl phosphate synthetase (C) Ornithine transcarbamoylase (D) None of these
Description : Which of the following is present as a marker in lysosomal enzymes to direct them to their destination? (A) Glucose-6-phosphate (B) Mannose-6-phosphate (C) Galactose-6-phosphate (D) N-Acetyl neuraminic acid
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 : How N-acetyl neuraminic acid (sialic acid) is synthesised?
Last Answer : N-acetyl mannosamine-6-phosphate + phospho enol pyruvate.
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
Description : Pyrimidine biosynthesis begins with the formation from glutamine, ATP and CO2, of (A) Carbamoyl aspartate (B) Orotate (C) Carbamoyl phosphate (D) Dihydroorotate
Description : Which of the following contributes nitrogen atoms to both purine and pyrimidine rings? (A) Aspartate (B) Carbamoyl phosphate (C) CO2 (D) Glutamine
Last Answer : Answer : A
Description : Cytosolic carbamoyl phosphate synthetase is inhibited by (A) UTP (B) CTP (C) PRPP (D) TMP
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 : An important finding in Hyperammonemia type II is (A) Increased serum gluatmine level (B) Enlarged liver (C) Mental retardation (D) Increased carbamoyl phosphate synthetase level
Description : Control of urea cycle involves the enzyme: (A) Carbamoyl phosphate synthetase (B) Ornithine transcarbamoylase (C) Argininosuccinase (D) Arginase
Description : The enzyme carbamoyl phosphate synthetase requires (A) Mg++ (B) Ca++ (C) Na+ (D) K+
Description : CTP synthetase forms CTP from (A) CDP and inorganic phosphate (B) CDP and ATP (C) UTP and glutamine (D) UTP and glutamate
Description : In urea synthesis, the amino acid functioning solely as an enzyme activator: (A) N-acetyl glutamate(B) Ornithine (C) Citrulline (D) Arginine
Description : Carbon skeleton of the following amino acid can serve as a substance for gluconeogenesis (A) Cysteine (B) Aspartate (C) Glutamate (D) All of these
Description : Which amino acid is present at 6th position of β-chain of Hbs instead of glutamate in HbA? (A) Cysteine (B) Valine (C) Aspartate (D) Glutamate
Description : The amino acid that undergoes oxidative deamination at significant rate is (A) Alanine (B) Aspartate (C) Glutamate (D) Glutamine
Description : All of the following statements about aspartate are true except (A) It is non-essential amino acid (B) It is a dicarboxylic amino acid (C) It can be synthesized from pyruvate and glutamate (D) It can be converted into asparagine
Description : L-glutamic acid is subjected to oxidative deaminition by (A) L-amino acid dehydrogenase (B) L-glutamate dehydrogenase (C) Glutaminase (D) Glutamine synthetase
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 : 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 : 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 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
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 : In purine nucleus nitrogen atom at 1 position is derived from (A) Aspartate (B) Glutamate (C) Glycine (D) Alanine
Description : Niacin is synthesized in the body from (A) Tryptophan (B) Tyrosine (C) Glutamate (D) Aspartate
Description : Carnitine is synthesized from (A) Lysine and methionine (B) Glycine and arginine (C) Aspartate and glutamate (D) Proline and hydroxyproline
Description : In brain, the major metabolism for removal of ammonia is the formation of (A) Glutamate (B) Aspartate (C) Asparagine (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 : Electrostatic bonds can be formed between the side chains of (A) Alanine and leucine (B) Leucine and valine (C) Asparate and glutamate (D) Lysine and aspartate
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 : The most of the ultraviolet absorption of proteins above 240 nm is due to their content of (A) Tryptophan (B) Aspartate (C) Glutamate (D) Alanine
Last Answer : (A) Tryptophan
Description : A key substance in the committed step of pyrimidines biosynthesis is (A) Ribose-5-phosphate (B) Carbamoyl phosphate (C) ATP (D) Glutamine
Description : The highest energy level is present amongst the following in (A) 1, 3-Biphosphoglycerate (B) Creatine phosphate (C) Carbamoyl phosphate (D) Phosphoenol pyruvate
Description : ATP is required in following reactions of urea cycle: (A) Synthesis of carbamoyl phosphate and citrulline (B) Synthesis of citrulline and argininosuccinate (C) Synthesis of argininosuccinate and arginine (D) Synthesis of carbamoyl phosphate and argininosuccinate
Description : Carbamoyl phosphate required for urea synthesis is formed in (A) Cytosol (B) Mitochondria (C) Both (A) and (B) (D) None of these
Description : Thiamine is essential for (A) Pyruvate dehydrogenase (B) Isocitrate dehydrogenase (C) Succinate dehydrogenase (D) Acetyl CoA synthetase ENZYMES 165
Description : Formation of acetyl CoA from pyruvate for de novo synthesis of fatty acids requires (A) Pyruvate dehydrogenase complex (B) Citrate synthetase (C) ATP citrate lyase (D) All of these
Description : Carboxylation of acetyl-CoA to malonylCoA requires the enzyme: (A) Acetyl-CoA carboxylase (B) Pyruvate carboxylase (C) Acetyl transacylase (D) Acyl CoA-synthetase
Description : The ‘Committed step’ in the biosynthesis of cholesterol from acetyl CoA is (A) Formation of acetoacetyl CoA from acetyl CoA (B) Formation of mevalonate from HMG CoA (C) Formation of HMG CoA from acetyl CoA and acetoacetyl CoA (D) Formation of squalene by squalene synthetase