Description : HMG-CoA is converted to mevalonate by reduction catalysed by (A) HMG-CoA synthetase (B) HMG-CoA reductase (C) Mevalonate kinase (D) Thiolase
Last Answer : Answer : B
Description : The carbon chain of fatty acids is shortened by 2 carbon atoms at a time. This involves successive reactions catalysed by 4-enzymes. These act the following order: (A) Acetyl CoA dehydrogenase, ... CoA dehydrogenase (D) Enoyl hydrase, β-OH acyl CoA dehydrogenase, acyl CoA dehydrogenase, thiolose,
Description : Acetoacetyl-CoA condenses with one more molecule of acetyl-CoA to form (A) Mevalonate (B) Acetoacetate (C) β-Hydroxybutyrate (D) 3-Hydroxy 3-methyl-glutaryl-CoA
Last Answer : Answer : D
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
Last Answer : Answer : A
Description : The starting material for ketogenesis is (A) Acyl-CoA (B) Acetyl-CoA (C) Acetoacetyl-CoA (D) Malonyl-CoA
Last Answer : Answer : C
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 ‘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 : While citrate is converted to isocitrate in the mitochondria, it is converted to _______ in the cytosol. (A) Acetyl CoA + oxaloacetate (B) Acetyl CoA + malonyl CoA (C) Acetyl CoA + Pyruvate (D) Acetyl CoA + acetoacetyl CoA
Description : Propionyl CoA formed oxidation of fatty acids having an odd number of carbon atoms is converted into (A) Acetyl CoA (B) Acetoacetyl CoA (C) D-Methylmalonyl CoA (D) Butyryl CoA
Description : Acetyl-CoA is the principal building block of fatty acids. It is produced within the mitochondria and does not diffuse readily into cytosol. The availability of acetyl CoA involves (A) Carnitine acyl transferase (B) Pyruvate dehydrogenase (C) Citrate lyase (D) Thiolase
Description : Acetyl CoA required for extra mitochondrial fatty acid synthesis is produced by (A) Pyruvate dehydrogenase complex (B) Citrate lyase (C) Thiolase (D) Carnitine-acyl transferase
Description : Cholesterol by a feed back mechanism inhibits the activity of (A) HMG-CoA synthetase (B) HMG-CoA reductase (C) Thilase (D) Mevalonate kinase
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 : The rage limiting step cholesterol biosynthesis is (A) Squalene synthetase (B) Mevalonate kinase (C) HMG CoA synthetase (D) HMG CoA reductase
Description : The rate limiting reaction in the lipogenic pathway is (A) Acetyl-CoA carboxylase step (B) Ketoacyl synthase step (C) Ketoacyl reductase step (D) Hydratase step
Description : Lovastatin is a (A) Competitive inhibitor of acetyl CoA carboxylase (B) Competitive inhibitor of HMG CoA synthetase (C) Non-competitive inhibitor of HMG CoA reductase (D) Competitive inhibitor of HMG CoA reductase
Description : An enzyme required for the synthesis of ketone bodies as well as cholesterol is (A) Acetyl CoA carboxylase (B) HMG CoA synthetase (C) HMG CoA reductase (D) HMG CoA lyase
Description : Conversion of pyruvate into acetyl CoA is catalysed by (A) Pyruvate dehydrogenase (B) Didrolipoyl acetyl transferase (C) Dihydrolipoyl dehydrogenase (D) All the 3 acting in concert
Description : In gluconeogensis, an allosteric activator required in the synthesis of oxaloacetate from bicarbonate and pyruvate, which is catalysed by the enzyme pyruvate carboxylase is (A) Acetyl CoA (B) Succinate (C) Isocitrate (D) Citrate
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 : Insulin decreases the activity of (A) cAMP dependent protein kinase (B) HMG CoA-reductas (C) Phosphodiesterase (D) Acetyl CoA-carboxylase
Description : Pyruvate dehydrogenase is a/an (A) Isomerase (B) Lyase (C) Ligase (D) Oxido reductase
Description : In biosynthesis of cholesterol triparanol inhibits the activity of the enzyme: (A) ∆24 Reductase (B) Oxidosqualene-lanosterol cyclase (C) Isomerase (D) Squalene epoxidase ENZYMES 155
Description : The enzyme involved in essential pentosuria is (A) Reductase (B) Hydroxylase (C) Isomerase (D) Racemase
Description : From arachidonate, synthesis of prostaglandins is catalysed by (A) Cyclooxygenase (B) Lipoxygenase (C) Thromboxane synthase (D) Isomerase
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 : In β-oxidation 3-ketoacyl-CoA is splitted at the 2, 3 position by the enzyme: (A) Hydratase (B) Dehydrogenase (C) Reducatse (D) Thiolase
Description : The formation of ∆2-trans-enoyl-CoA from acyl-CoA requires the enzyme: (A) Acyl-CoA synthetase (B) Acyl-CoA dehydrogenase (C) 3-Hydroxy acyl-CoA dehydrogenase (D) Thiolase
Description : For each of the first 7-acetyl-CoA molecules formed by α-oxidation of palmitic acid, the yield of high energy phosphates is (A) 12 (B) 24 (C) 30 (D) 35
Description : The number of molecules of ATP produced by the total oxidation of acetyl CoA in TCA cycle is (A) 6 (B) 8 (C) 10 (D) 12
Last Answer : D
Description : An enzyme involved in gluconeogenesis is (A) Pyruvate kinase (B) Pyruvate carboxylase (C) Hexokinase (D) Phosphohexose isomerase
Description : In glycolytic pathway, iodacetate inhibits the activity of the enzyme: (A) Phosphotriose isomerase (B) Glyceraldehyde-3-phosphate dehydrogenase (C) Pyruvate kinase (D) Phosphofructokinase
Description : ATP is ‘wasted’ in Rapoport-Lueberring cycle in RBCs as otherwise it will inhibit (A) Phosphoglucomutase (B) Phosphohexo isomerase (C) Phosphofructo kinase (D) Phosphoenol pyruvate carboxy kinase
Last Answer : C
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 : Conversion of fructose to sorbitol is catalysed by the enzyme: (A) Sorbitol dehydrogenase (B) Aldose reductase (C) Fructokinase (D) Hexokinase
Description : Phosphorylation of adenosine to AMP is catalysed by (A) Adenosine kinase (B) Deoxycytidine kinase (C) Adenylosuccinase (D) Adenylosuccinate synthetase
Description : Synthesis of phosphatidylinositol by transfer of inositol to CDP diacylglycerol is catalysed by the enzyme: (A) CTP phosphatidate cytidyl transferase (B) Phosphatidate phosphohydrolase (C) CDP-diacylglycerol inositol transferase (D) Choline kinase
Description : During which stage in the complete oxidation of glucose are the greatest number of ATP molecules formed from ADP? (a) Glycolysis (b) Krebs’ cycle (c) Conversion of pyruvic acid to acetyl CoA (d) Electron transport chain
Last Answer : (d) Electron transport chain
Description : HMG-CoA reductase activity is increased by administration of the hormone: (A) Insulin (B) Glucagon (C) Epinephrine (D) Glucocorticoids
Description : The activity of HMG-CoA reductase is inhibited by (A) A fungal inhibitor mevastatin (B) Probucol (C) Nicotinic acid (D) Clofibrate
Description : For reduction enzyme HMG-CoA reductase requires cofactor: (A) NADPH (B) NADP (C) NAD (D) FAD
Description : Synthesis of polyunsaturated fatty acids involves the enzyme systems: (A) Acyl transferase and hydratase (B) Desaturase and elongase (C) Ketoacyl-CoA reductase and hydratase (D) Dihydroxyacetone phosphate
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
Description : Riboflavin is a coenzyme in the reaction catalysed by the enzyme (A) Acyl CoA synthetase (B) Acyl CoA dehydrogenase (C) β-Hydroxy acyl CoA (D) Enoyl CoA dehydrogenase
Description : This catalyzes formation of CoA derivatives from fatty acid, CoA and ATP: (A) Acyl CoA dehydrogenase (B) Enoyl hydrase (C) β-OH acyl CoA dehydrogenase (D) Thio kinase
Description : All the following statements about acetyl CoA carboxylase are true except (A) It is required for de novo synthesis of fatty acids (B) It is required for mitochondrial elongation of fatty acids ( ... for microsomal elongation of fatty acids (D) Insulin converts its inactive form into its active form
Description : All the following statements about acetyl CoA carboxylase are true except: (A) It is activated by citrate (B) It is inhibited by palmitoyl CoA (C) It can undergo covalent modification (D) Its dephosphorylated form is inactive
Description : Insulin regulates fatty acid synthesis by (A) Dephosphorylating of acetyl CoA carboxylase (B) Activating phosphorylase (C) Inhibiting malonyl CoA formation (D) Controlling carnitine-Acyl CoA transferase activity
Description : Thiamine is essential for (A) Pyruvate dehydrogenase (B) Isocitrate dehydrogenase (C) Succinate dehydrogenase (D) Acetyl CoA synthetase ENZYMES 165
Description : Which one of the following cofactors must be utilized during the conversion of acetyl CoA to malonyl CoA? (A) TPP (B) ACP (C) NAD+ (D) Biotin