Description : The condensation of 2 molecules of δ-aminolevulinate dehydratase contains (A) ALA synthase (B) ALA hydratase (C) Uroporphyrinogen synthase I (D) Uroporphyrinogen synthase III
Last Answer : Answer : B
Description : In the biosynthesis of heme, condensation between succinyl CoA and glycine requires (A) NAD+ (B) FAD (C) NADH + H+ (D) B6-phosphate
Last Answer : Answer : D
Description : Conversion of the linear tetrapyrrole hydroxymethylbilane to uroporphyrinogen III (A) Occurs spontaneously (B) Catalysed by uroporphyrinogen I synthase (C) Catalysed by uroporphyrinogen III cosynthase (D) Catalysed by combined action of uroporphyrinogen I synthase and uroporphyrinogen III cosynthase
Description : The example of generation of a high energy phosphate at the substrate level in the citric acid cycle is the reaction: (A) Isocitrate α-Ketoglutarate (B) Succinate α-fumarate (C) Malate α-oxaloacetate (D) Succinyl CoA α-Succinate
Description : β-Oxidation of odd-carbon fatty acid chain produces (A) Succinyl CoA (B) Propionyl CoA (C) Acetyl CoA (D) Malonyl CoA
Description : Heme is synthesized from (A) Succinyl-CoA and glycine (B) Active acetate and glycine (C) Active succinate and alanine (D) Active acetate and alanine
Last Answer : Answer : A
Description : Which statement is wrong for Krebs' cycle? (a) There is one point in the cycle where FAD+ is reduced to FADH2. (b) During conversion of succinyl CoA to succinic acid, a molecule of GTP is synthesised. (c ... citric acid. (d) There are three points in the cycle where NAD+ is reduced to NADH + H+.
Last Answer : (c) The cycle starts with condensation of acetyl group (acetyl CoA) with pyruvic acid to yield citric acid.
Description : Formation of succinyl-CoA from α-Ketoglutarate is inhibited by (A) Fluoroacetate (B) Arsenite (C) Fluoride (D) Iodoacetate
Description : In Krebs’ cycle, the FAD precipitates as electron acceptor during the conversion of (a) fumaric acid to malic acid (b) succinic acid to fumaric acid (c) succinyl CoA to succinic acid (d) α-ketoglutarate to succinyl CoA.
Last Answer : (b) succinic acid to fumaric acid
Description : The enzyme δ-aminolevulinate dehydratase contains (A) Zinc (B) Manganese (C) Magnesium (D) Calcium
Description : The characteristic urinary finding in porphyria cutanea tarda is (A) Increased quantity of porphobilinogen (B) Increased quantity of red cell protoporphyrin (C) Increased quantity of uroporphyrin (D) Increased quantity of δ-ALA
Last Answer : Answer : C
Description : The initial step of the citric acid cycle is (A) Conversion of pyruvate to acetyl-CoA (B) Condensation of acetyl-CoA with oxaloacetate (C) Conversion of citrate to isocitrate (D) Formation of α -ketoglutarate catalysed by isocitrate dehydrogenase
Description : Synthesis of RNA molecule is terminated by a signal which is recognised by (A) α-factor (B) β-factor (C) δ-factor (D) ρ
Description : The mammalian DNA polymerase involved in error correction is (A) DNA polymerase α (B) DNA polymerase β (C) DNA polymerase γ (D) DNA polymerase δ
Description : Primase activity is present in (A) DNA polymerase II (B) DNA polymerase α (C) DNA polymerase β (D) DNA polymerase δ
Description : Insulin receptor is made up of (A) One α-and one β-subunit (B) Two α-and two β-subunit (C) Two, α two β-and two γ-subunit (D) One α, one β-one γ-and one δ-subunit
Description : In the insulin receptor, tyrosine kinase domain is present in (A) α-Subunits (B) β-Subunits (C) γ-Subunits (D) δ-Subunits
Description : The nucleotide binding site of G-proteins is present on their (A) α-Subunit (B) β-Subunit α- and β- (C) γ-Subunit (D) δ-Subunit
Description : In synthesis of Triglyceride from α-Glycero phosphate and acetyl CoA, the first intermediate formed is (A) β-diacyl glycerol (B) Acyl carnitine (C) Monoacyl glycerol(D) Phosphatidic acid
Description : In mammalian liver the rate controlling enzyme in porphyrin biosynthesis is (A) ALA synthase (B) ALA hydratase (C) Uroporphyrinogen I synthase (D) Uroporphyrinogen III cosynthase
Description : All α-amino acids have one asymmetric carbon atom except (A) Arginine (B) Glycine (C) Aspartic acid (D) Histidine
Description : FAD containing enzyme, catalyzing formation of α, β unsaturated fatty acyl CoA derivative. (A) Acyl CoA dehydrogenase (B) Enoyl hydrase (C) β-OH acyl CoA dehydrogenase (D) Thiolase
Description : Acyl-CoA dehydrogenase converts Acyl CoA to α-β unsaturated acyl-CoA in presence of the coenzyme: (A) NAD+ (B) NADP+ (C) ATP (D) FAD
Description : The α-carbon of all the amino acids is a chirality center except for __________. (a) Glycine (b) Threonine (c) Proline (d) Aspartic acid
Last Answer : Glycine
Description : The source of all the carbon atoms in cholesterol is (A) Acetyl-CoA (B) Bicarbonate (C) Propionyl-CoA (D) Succinyl-CoA
Description : Conversion of fatty acyl-CoA to an acylCoA derivative having 2 more carbon atoms involves as acetyl donar: (A) Acetyl-CoA (B) Succinyl-CoA (C) Propionyl-CoA (D) Malonyl-CoA
Description : In extra hepatic tissues, one mechanism for utilization of acetoacetate involves (A) Malonyl-CoA (B) Succinyl-CoA (C) Propionyl-CoA (D) Acetyl-CoA
Description : Fatty acids with odd number of carbon atoms yield acetyl-CoA and a molecule of (A) Succinyl-CoA (B) Propionyl-CoA (C) Malonyl-CoA (D) Acetoacetyl-CoA
Description : The reaction succinyl COA to succinate requires (A) CDP (B) ADP (C) GDP (D) NADP+
Last Answer : B
Description : Succinyl CoA is utilised for what purposes?
Last Answer : Porphyrin biosynthesis, activation of acetoacetate, and oxidation in TCA cycle.
Description : Succinyl CoA is generated from which substances?
Last Answer : Odd chain fatty acids, propionic acid, valine, isoleucine, threonine.
Description : What are the co-enzymes required for the conversion of propionyl CoA to succinyl CoA?
Last Answer : Biotin, ATP, Vitamin B12.
Description : Which of the following products of triacylglycerol breakdown and subsequent β-Oxidation may undergo gluconeogenesis? (A) Acetyl CoA (B) Porpionyl CoA (C) All ketone bodies (D) Some amino acids
Description : In the biosynthesis of triglycerides from glycerol 3-phosphate and acyl-CoA, the first intermediate formed is (A) 2-Monoacylglycerol (B) 1, 2-Diacylglycerol (C) Lysophosphatidic acid (D) Phosphatidic acid
Description : All statements regarding 3-OH-3 methyl glutaryl CoA are true except (A) It is formed in the cytoplasm (B) Required in ketogenesis (C) Involved in synthesis of Fatty acid (D) An intermediate in cholesterol biosynthesis
Description : The only known physiological methylating agents in the animal organism are (A) Choline and betaine (B) Choline and δ-adenosyl methionine (C) Betaine and δ-adenyosyl methionine (D) Dimehtyl glycine and betaine
Description : Thyroid stimulating hormone is a dimer. The α-subunits of TSH, LH, FSH are identical. Thus the biological specificity must therefore be β subunit in which the number of amino acids is (A) 78 (B) 112 (C) 130 (D) 199
Description : Pyrimidine and purine nucleoside biosynthesis share a common precursor: (A) PRPP (B) Glycine (C) Fumarate (D) Alanine
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 : Claisen condensation gives__________ a) Hydroxyl compound b) β- keto ester c) Γ- diketone d) Α-diketone
Last Answer : b) β- keto ester
Description : In the biosynthesis of cholesterol, the rate limiting enzyme is (A) Mevalonate kinase (B) HMG-CoA synthetase (C) HMG-CoA reductase (D) Cis-prenyl transferase
Description : In the biosynthesis of cholesterol, the step which controls the rate and locus of metabolic regulation is (A) Geranyl pyrophosphate farnesyl pyrophosphate (B) Squalene → lanosterol (C) HMG CoA → mevalonate (D) Lanosterol → 1, 4-desmethyl lanosterol
Description : In the pathway leading to biosynthesis of acetoacetate from acetyl-CoA in liver, the immediate precursor of aceotacetate is (A) Acetoacetyl-CoA (B) 3-Hydroxybutyryl-CoA (C) 3-Hydroxy-3-methyl-glutaryl-CoA (D) 3-Hydroxybutyrate
Description : The rage limiting step cholesterol biosynthesis is (A) Squalene synthetase (B) Mevalonate kinase (C) HMG CoA synthetase (D) HMG CoA reductase
Description : A metabolite which is common to pathways of cholesterol biosynthesis from acetyl-CoA and cholecalciferol formation from cholesterol is (A) Zymosterol (B) Lumisterol (C) Ergosterol (D) 7 Dehydrocholesterol
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
Description : During synthesis of porphyrins, synthesis of δ-amino levulinic acid occurs in (A) Mitochondria (B) Cytosol (C) Both in mitochondria and cytosol (D) Ribosomes
Description : Which of the following statement regarding β-oxidation is true? (A) Requires β-ketoacyl CoA as a substrate (B) Forms CoA thioesters (C) Requires GTP for its activity (D) Yields acetyl CoA as a product
Description : The biosynthesis of both Catecholamine and serotonin require (A) Tyrosine hydroxylase (B) N-methyl transferase (C) Aromatic amino acid decarboxylase (D) Tryptophan pyrrolase
Description : For biosynthesis of proteins (A) Amino acids only are required (B) Amino acids and nucleic acids only are required (C) Amino acid, nucleic acids and ATP only are required (D) Amino acids, nucleic acids, ATP, GTP, enzymes and activators are required