Description : Pyruvate dehydrogenase complex and α-ketoglutarate dehydrogenase complex require the following for their oxidative decarboxylation: (A) COASH and Lipoic acid (B) NAD+ and FAD (C) COASH and TPP (D) COASH, TPP,NAD+,FAD, Lipoate
Last Answer : D
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 : All the following are coenzymes except (A) Ubiquinone (B) CoA (C) Pyruvate dehydrogenase (D) Lipoic acid
Last Answer : Answer : C
Description : The reaction catalysed by α-ketoglutarate dehydrogenase in the citric acid cycle requires (A) NAD (B) NADP (C) ADP (D) ATP
Last Answer : Answer : A
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 : All of the following are required for synthesis of alanine except (A) Pyruvate (B) α-ketoglutarate (C) Glutamate (D) Pyridoxal phosphate
Description : Alanine can be synthesized from (A) Glutamate and α-ketoglutarate (B) Pyruvate and glutamate (C) Pyruvate and α-ketoglutarate (D) Asparate and α-ketoglutarate
Description : Isocitrate dehydrogenase is allosterically inhibited by (A) Oxalosuccinate (B) α-Ketoglutarate (C) ATP (D) NADH
Description : Malonate is an inhibitor of (A) Malate dehydrogenase (B) α-Ketoglutarate dehydrogenase (C) Succinate dehydrogenase (D) Isocitrate dehydrogenase
Description : The hexose monophosphate pathway includes the enzyme: (A) Maltase dehydrogenase (B) Hexokinase (C) α-Ketoglutarate dehydrogenase (D) Glucose-6-phosphate dehydrogenase
Last Answer : Answer : D
Description : In TCA cycle, oxalosuccinate is converted to α-ketoglutarate by the enzyme: (A) Fumarase (B) Isocitrate dehydrogenase (C) Aconitase (D) Succinase
Description : Mitochondrial α-ketoglutarate dehydrogenase complex requires all the following to function except (A) CoA (B) FAD (C) NAD+ (D) NADP+
Description : A competitive inhibitor of succinic dehydrogenase is (a) α-ketoglutarate (b) malate (c) malonate (d) oxaloacetate.
Last Answer : (c) malonate
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 : The enzyme -ketoglutarate dehydrogenase in the citric acid cycle requires (A) Lipoate (B) Folate (C) Pyridoxine (D) Inositol
Description : All of the following intermediates of citric acid cycle can be formed from amino acids except (A) α-Ketoglutarate (B) Fumarate (C) Malate (D) Oxaloacetate
Description : Fluoroacetate inhibits the reaction of citric acid cycle: (A) Isocitrate α-Ketoglutarate (B) Fumarate α-Malate (C) Citrate α-cis-aconitate (D) Succinate α-fumarate
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 : Before pyruvic acid enters the TCA cycle it must be converted to (A) Acetyl CoA (B) Lactate (C) α-ketoglutarate (D) Citrate
Last Answer : A
Description : NAD is required as a conenzyme in (A) Citric acid cycle (B) HMP shunt (C) β-Oxidation of fatty acids (D) Both (A) and (C)
Description : All of the following are allosteric enzymes except (A) Citrate synthetase (B) a-Ketoglutarate dehdrogenase (C) Succinate thiokinase (D) Succinate dehydrogenase
Description : The reaction of Kreb’s cycle which does not require cofactor of vitamin B group is (A) Citrate isocitrate (B) α -Ketoglutarate succinate (C) Malate oxaloacetate (D) Succinate fumarate
Description : Formation of succinyl-CoA from α-Ketoglutarate is inhibited by (A) Fluoroacetate (B) Arsenite (C) Fluoride (D) Iodoacetate
Description : An important finding in Histidinemia is (A) Impairment of conversion of α-Glutamate to α-ketoglutarate (B) Speech defect (C) Decreased urinary histidine level (D) Patients can not be treated by diet
Description : Which one of the following compounds cannot give rise to the net synthesis of Glucose? (A) Lactate (B) Glycerol (C) α-ketoglutarate (D) Acetyl CoA
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 : 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 : Pyruvate dehydrogenase complex is regulated by (A) Covalent modification (B) Allosteric regulation (C) Both (A) and (B) (D) None of these
Description : The following ketoacid is involved in fixing dietary NH3 into amino acid: (A) Pyruvate (B) Oxalo acetate (C) Oxalo succinate (D) α-keto glutarate
Description : A mitochondrial marker enzyme is (A) Aldolase (B) Amylase (C) Succinic dehydrogenase (D) Pyruvate dehydrogenase ENZYMES 175
Description : Pyruvate dehydrogenase contains all except (A) Biotin (B) NAD (C) FAD (D) CoA
Description : Pyruvate dehydrogenase is a/an (A) Isomerase (B) Lyase (C) Ligase (D) Oxido reductase
Description : Thiamine is essential for (A) Pyruvate dehydrogenase (B) Isocitrate dehydrogenase (C) Succinate dehydrogenase (D) Acetyl CoA synthetase ENZYMES 165
Description : Coenzymes derived from the vitamin shown below are required by which of the following enzymes? (A) Lactate dehydrogenase (B) Glutamate dehydrogenase (C) Pyruvate dehydrogenase (D) Malate dehydrogenase
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 : Which of the following enzymes incorporates inorganic phosphate into the substrate? (A) Phosphoglycerate kinase (B) Glyceraldehyde-3-phosphate dehydrogenase (C) Pyruvate kinase (D) Enolase
Description : An allosteric inhibitor of pyruvate dehydrogenase is (A) Acetyl CoA (B) ATP (C) NADH (D) Pyruvate
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 : Pyruvate dehydrogenase complex is located in (A) Cytosol (B) Lysosomes (C) Mitochondria (D) Endoplasmic reticulum
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 : Biotin is a coenzyme for (A) Pyruvate dehydrogenase (B) Pyruvate carboxylase (C) PEP carboxykinase (D) Glutamate pyruvate transminase
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 : Acute hemolytic anemia in person’s sensitive to the Fava beans is due to the deficiency of the enzyme: (A) Pyruvate dehydrogenase (B) G-6-PD (C) Aconitase (D) Transketolase
Description : Insulin has no effect on the activity of the enzyme: (A) Glycogen synthetase (B) Fructokinase (C) Pyruvate kinase (D) Pyruvate dehydrogenase
Description : Pyruvate dehydrogenase activity is inhibited by (A) Mercury (B) Zinc (C) Calcium (D) Sodium
Description : Dietary deficiency of thiamin inhibits the activity of the enzyme: (A) Pyruvate kinase (B) Pyruvate dehydrogenase (C) Phosphofructokinase (D) Enolase
Description : Pyruvate dehydrogenase a multienzyme complex is required for the production of (A) Acetyl-CoA (B) Lactate (C) Phosphoenolpyruvate (D) Enolpyruvate
Description : Enzymes leading to the high energy phosphorylation of substrates during glycolysis include which of the following? (A) Phosphoglycerate kinase (B) Enolase (C) Pyruvate Kinase (D) Glyceraldehyde-3-phosphate dehydrogenase
Description : In the glycolytic pathway, enolpyruvate is converted to ketopyruvate by (A) Pyruvate kinase (B) Phosphoenolpyruvate (C) Pyruvate dehydrogenase (D) Spontaneously