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
Last Answer : Answer : D
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
Last Answer : Answer : C
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 : 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 : 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 : Malonate is an inhibitor of (A) Malate dehydrogenase (B) α-Ketoglutarate dehydrogenase (C) Succinate dehydrogenase (D) Isocitrate dehydrogenase
Description : The substance which may be considered to play a catalytic role in citric acid cycle is (A) Oxaloacetate (B) Isocitrate (C) Malate (D) Fumarate
Last Answer : Answer : A
Description : The carrier of the citric acid cycle is (A) Succinate (B) Fumarate (C) Malate (D) Oxaloacetate
Last Answer : D
Description : A compound serving a link between citric acid cycle and urea cycle is (A) Malate (B) Citrate (C) Succinate (D) Fumarate
Description : The metabolism of protein is integrated with that of carbohydrate and fat through (A) Oxaloacetate (B) Citrate (C) Isocitrate (D) Malate
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 : For extramitochondrial fatty acid synthesis, acetyl CoA may be obtained from (A) Citrate (B) Isocitrate (C) Oxaloacetate (D) Succinate
Description : A competitive inhibitor of succinic dehydrogenase is (a) α-ketoglutarate (b) malate (c) malonate (d) oxaloacetate.
Last Answer : (c) malonate
Description : The integrator between the TCA cycle and urea cycle is (A) Fumarate (B) Malate (C) Pyruvate (D) Citrate
Description : Among citric acid cycle enzymes, a flavoprotein is (A) Malate (B) Fumarase (C) Succinate dehrogenase (D) Isocitrate dehrogenase
Description : Substrate level phosphorylation in TCA cycle is in step: (A) Isocitrate dehydrogenase (B) Malate dehydrogenase (C) Aconitase (D) Succinate thiokinase
Description : A carrier molecule in the citric acid cycle is (A) Acetyl-CoA (B) Citrate (C) Oxaloacetate (D) Malate
Description : Mitochondrial membrane is freely preamble to (A) Pyruvate (B) Malate (C) Oxaloacetate (D) Fumarate
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 : An aneplerotic reaction which sustains the availability of oxaloacetate is the carboxylation of (A) Glutamate (B) Pyruvate (C) Citrate (D) Succinate
Last Answer : B
Description : Active transport of sugar is depressed by the agent: (A) Oxaloacetate (B) Fumarate (C) Malonate (D) Succinate
Last Answer : C
Description : In TCA cycle, oxalosuccinate is converted to α-ketoglutarate by the enzyme: (A) Fumarase (B) Isocitrate dehydrogenase (C) Aconitase (D) Succinase
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 : 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 : All of the following are allosteric enzymes except (A) Citrate synthetase (B) a-Ketoglutarate dehdrogenase (C) Succinate thiokinase (D) Succinate dehydrogenase
Description : Out of 24 mols of ATP formed in TCA cycle, 2 molecules of ATP can be formed at “substrate level” by which of the following reaction ? (A) Citric acid→ Isocitric acid (B) Isocitrate→ Oxaloacetate (C) Succinic acid→ Fumarate (D) Succinylcat→ Succinic acid
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 : Isocitrate dehydrogenase is allosterically inhibited by (A) Oxalosuccinate (B) α-Ketoglutarate (C) ATP (D) NADH
Description : All of the following compounds are intermediates of TCA cycle except (A) Maleate (B) Pyruvate (C) Oxaloacetate (D) Fumarate
Description : All of the following are intermediates of citric acid cycle except (A) Oxalosuccinate (B) Oxaloacetate (C) Pyruvate (D) Fumarate
Description : An allosteric enzyme responsible for controlling the rate of T.C.A cycle is (A) Malate dehydrogenase (B) Isocitrate dehydrogenase (C) Fumarase (D) Aconitase
Description : The reaction catalysed by α-ketoglutarate dehydrogenase in the citric acid cycle requires (A) NAD (B) NADP (C) ADP (D) ATP
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
Description : Connecting link between glycolysis and Krebs’ cycle before pyruvate entering Krebs’ cycle is changed to (a) oxaloacetate (b) PEP (c) pyruvate (d) acetyl CoA.
Last Answer : (d) acetyl CoA.
Description : NADPH required for fatty acid synthesis can come from (A) Hexose monophosphate shunt (B) Oxidative decarboxylation of malate (C) Extramitochondrial oxidation of isocitrate (D) All of these
Description : Isocitrate dehydrogenase can use __________ as a cofactor. (A) NAD+ only (B) NADP+ only (C) NAD+ or NADP+ (D) FMN and FAD
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 : In presence of the following cofactor, pyruvate carboxylase converts pyruvate to oxaloacetate: (A) ATP, Protein and CO2 (B) CO2 and ATP (C) CO2 (D) Protein
Description : Calcium is required for the activation of the enzyme: (A) Isocitrate dehydrogenase (B) Fumarase (C) Succinate thiokinase (D) ATPase
Description : Thiamine is essential for (A) Pyruvate dehydrogenase (B) Isocitrate dehydrogenase (C) Succinate dehydrogenase (D) Acetyl CoA synthetase ENZYMES 165
Description : With the exception of glycine all amino acids found in protein are (A) Isocitrate dehydrogenase (B) Fumarase (C) Succinate thiokinase (D) ATPase
Description : Which of the following is not having an apoenzyme and coenzyme? (A) Lactate dehydrogenase (B) Succinate dehydrogenase (C) Malate dehydrogenase (D) Pepsin
Description : An enzyme catalyzing oxidoreduction, using oxygen as hydrogen acceptor is (A) Cytochrome oxidase (B) Lactate dehydrogenase (C) Malate dehydrogenase (D) Succinate 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 : NADPH is produced when this enzyme acts (A) Pyruvate dehydrogenase (B) Malic enzyme (C) Succinate dehydrogenase (D) Malate dehydrogenase
Description : Citrate is converted to isocitrate by aconitase which contains (A) Ca++ (B) Fe++ (C) Zn++ (D) Mg++
Description : Select the oral iron preparation which does not impart metallic taste and has good oral tolerability despite high iron content but whose efficacy in treating iron deficiency anaemia has been questioned: A. Iron hydroxy polymaltose B. Ferrous succinate C. Ferrous fumarate D. Ferrous gluconate
Last Answer : A. Iron hydroxy polymaltose
Description : A specific inhibitor for succinate dehydrogenase is (A) Arsenite (B) Malonate (C) Citrate (D) Fluoride
Description : A specific inhibitor for succinate dehydrogenase is (A) Arsenine (B) Arsenite (C) Citrate (D) Fluoride ENZYMES 147
Description : A specific inhibitor for succinate dehydrogenase is (A) Arsinite (B) Melouate (C) Citrate (D) Cyanide