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
Last Answer : Answer : A
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
Last Answer : Answer : B
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
Last Answer : Answer : D
Description : For extramitochondrial fatty acid synthesis, acetyl CoA may be obtained from (A) Citrate (B) Isocitrate (C) Oxaloacetate (D) Succinate
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 : All of the following are allosteric enzymes except (A) Citrate synthetase (B) a-Ketoglutarate dehdrogenase (C) Succinate thiokinase (D) Succinate dehydrogenase
Last Answer : Answer : C
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 : All enzymes of TCA cycle are located in the mitochondrial matrix except one which is located in inner mitochondrial membranes in eukaryotes and in cytosol in prokaryotes. This enzyme is (a) isocitrate dehydrogenase (b) malate dehydrogenase (c) succinate dehydrogenase (d) lactate dehydrogenase.
Last Answer : (c) succinate dehydrogenase
Description : Fully activated pyruvate carboxylase depends upon the presence of (A) Malate and Niacin (B) Acetyl CoA and biotin (C) Acetyl CoA and thiamine pyrophosphate (D) Oxaloacetate and biotin
Description : An allosteric inhibitor of pyruvate dehydrogenase is (A) Acetyl CoA (B) ATP (C) NADH (D) Pyruvate
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 : The principal action of insulin in adipose tissue is to inhibit the activity of the (A) Hormone sensitive lipoprotein lipase (B) Glycerol phosphate acyltransferase (C) Acetyl-CoA carboxylase (D) Pyruvate dehydrogenase
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 : Pyruvate dehydrogenase a multienzyme complex is required for the production of (A) Acetyl-CoA (B) Lactate (C) Phosphoenolpyruvate (D) Enolpyruvate
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 : Calcium is required for the activation of the enzyme: (A) Isocitrate dehydrogenase (B) Fumarase (C) Succinate thiokinase (D) ATPase
Description : Malonate is an inhibitor of (A) Malate dehydrogenase (B) α-Ketoglutarate dehydrogenase (C) Succinate dehydrogenase (D) Isocitrate dehydrogenase
Description : With the exception of glycine all amino acids found in protein are (A) Isocitrate dehydrogenase (B) Fumarase (C) Succinate thiokinase (D) ATPase
Description : Substrate level phosphorylation in TCA cycle is in step: (A) Isocitrate dehydrogenase (B) Malate dehydrogenase (C) Aconitase (D) Succinate thiokinase
Last Answer : D
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 : A flavoprotein in pyruvate dehydrogenase complex is (A) Pyruvate dehydrogenase (B) Didrolipoyl acetyl transferase (C) Dihydrolipoyl dehydrogenase (D) None of these ENZYMES 161
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 : An enzyme of the citric acid cycle also found outside the mitochondria is (A) Isocitrate dehydrogenase (B) Citrate synthetase (C) α-Ketoglutarate dehydrogenase (D) Malate dehydrogenase
Description : Among citric acid cycle enzymes, a flavoprotein is (A) Malate (B) Fumarase (C) Succinate dehrogenase (D) Isocitrate dehrogenase
Description : NADPH is produced when this enzyme acts (A) Pyruvate dehydrogenase (B) Malic enzyme (C) Succinate dehydrogenase (D) Malate dehydrogenase
Description : NAD is required as a coenzyme for (A) Malate dehydrogenase (B) Succinate dehydrogenase (C) Glucose-6-phosphate dehydrogenase (D) HMG CoA reductae
Description : Insulin has no effect on the activity of the enzyme: (A) Glycogen synthetase (B) Fructokinase (C) Pyruvate kinase (D) Pyruvate dehydrogenase
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 : 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 : 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 : 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 : A specific inhibitor for succinate dehydrogenase is (A) Arsenine (B) Arsenite (C) Citrate (D) Fluoride ENZYMES 147
Description : Pyruvate dehydrogenase contains all except (A) Biotin (B) NAD (C) FAD (D) CoA
Description : All the following are coenzymes except (A) Ubiquinone (B) CoA (C) Pyruvate dehydrogenase (D) Lipoic acid
Description : Acetyl CoA required for de novo synthesis of fatty acids is obtained from (A) Breakdown of existing fatty acids (B) Ketone bodies (C) Acetate (D) Pyruvate
Description : End product of aerobic glycolysis is (A) Acetyl CoA (B) Lactate (C) Pyruvate (D) CO2 and H2O
Description : Pyruvate is converted into acetyl-CoA by (A) Decarboxylation (B) Dehydrogenation (C) Oxidative decarboxylation (D) Oxidative deamination
Description : Acetyl-CoA can be formed from (A) Pyruvate (B) Fatty acids (C) ketone bodies (D) All of these
Description : The coenzyme not involved in the formation of acetyl-CoA from pyruvate is (A) TPP (B) Biotin (C) NAD (D) FAD
Description : Which of the following intermediates of metabolism can be both a precursor and a product of glucose? (A) Lactate (B) Pyruvate (C) Alanine (D) Acetyl-CoA
Description : Biotin is a coenzyme for (A) Pyruvate carboxylase (B) Acetyl CoA carboxylase (C) Propionyl CoA carboxylase (D) All of these
Description : Fatty acids can not be converted into carbohydrates in the body, as the following reaction is not possible: (A) Conversion of glucose-6-phosphate into glucose (B) Fructose 1, 6 diphosphate to ... phosphate (C) Transformation of acetyl CoA to pyruvate (D) Formation of acetyl CoA from fatty acids
Description : Acetyl CoA formed from pyruvate can be used for the synthesis of all the following except (A) Glucose (B) Fatty acids (C) Cholesterol (D) Steroid hormones
Description : The conversion of pyruvate to acetyl CoA and CO2 (A) Is reversible (B) Involves the participation of lipoic acid (C) Depends on the coenzyme biotin (D) Occurs in the cytosol
Last Answer : B
Description : Which of the following compound is a positive allosteric modifier of the enzyme pyruvate carboxylase? (A) Biotin (B) Acetyl CoA (C) Oxaloacetate (D) ATP
Last Answer : A
Description : When O2 supply is inadequate, pyruvate is converted to (A) Phosphopyruvate (B) Acetyl CoA (C) Lactate (D) Alanine
Last Answer : C
Description : Fatty acids cannot be converted into carbohydrates in the body as the following reaction is not possible. (A) Conversion of glucose-6-phosphate into glucose (B) Fructose 1,6-bisphosphate to fructose- ... (C) Transformation of acetyl CoA to pyruvate (D) Formation of acetyl CoA from fatty acids
Description : Which of the following metabolite integrates glucose and fatty acid metabolism? (A) Acetyl CoA (B) Pyruvate (C) Citrate (D) Lactate
Description : Pyruvate is converted to acetyl CoA by which enzyme?
Last Answer : Pyruvate dehydrogenate.