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 : In citric acid cycle, GDP is phosphorylated by (A) Succinate dehydrogenase (B) Aconitase (C) Succinate thiokinase (D) Fumarse
Last Answer : Answer : C
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 : In TCA cycle, oxalosuccinate is converted to α-ketoglutarate by the enzyme: (A) Fumarase (B) Isocitrate dehydrogenase (C) Aconitase (D) Succinase
Last Answer : Answer : B
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
Last Answer : B
Description : Oxidative phosphorylation involves (A) Electron transport system (B) Substrate level phosphorylation (C) Reaction catalyzed by succinic thiokinase in TCA cycle (D) None of the above
Last Answer : (A) Electron transport system
Description : Calcium is required for the activation of the enzyme: (A) Isocitrate dehydrogenase (B) Fumarase (C) Succinate thiokinase (D) ATPase
Description : With the exception of glycine all amino acids found in protein are (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 : Among citric acid cycle enzymes, a flavoprotein is (A) Malate (B) Fumarase (C) Succinate dehrogenase (D) Isocitrate dehrogenase
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
Last Answer : Answer : A
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 rate of citric acid cycle is controlled by the allosteric enzyme: (A) Aconitase (B) Fumarase (C) Fumarase (D) Malate dehydrogenase
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 : In the TCA cycle, at which of the following enzyme-catalyzed steps, incorporation of elements of water into an intermediate of the cycle takes place : (A) Citrate synthase (B) Aconitase (C) Maleate dehydrogenase (D) Succinyl Co-A synthase
Last Answer : (C) Maleate dehydrogenase
Description : Fluoride inhibits ______ and arrests glycolysis. (A) Glyceraldehyde-3-phosphate dehydrogenase (B) Aconitase (C) Enolose (D) Succinate dehydrogenase
Last Answer : C
Description : All of the following are allosteric enzymes except (A) Citrate synthetase (B) a-Ketoglutarate dehdrogenase (C) Succinate thiokinase (D) Succinate dehydrogenase
Description : Thiamine is essential for (A) Pyruvate dehydrogenase (B) Isocitrate dehydrogenase (C) Succinate dehydrogenase (D) Acetyl CoA synthetase ENZYMES 165
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 : 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 : The substance which may be considered to play a catalytic role in citric acid cycle is (A) Oxaloacetate (B) Isocitrate (C) Malate (D) Fumarate
Description : The integrator between the TCA cycle and urea cycle is (A) Fumarate (B) Malate (C) Pyruvate (D) Citrate
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
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 carrier of the citric acid cycle is (A) Succinate (B) Fumarate (C) Malate (D) Oxaloacetate
Description : Citrate is converted to isocitrate by aconitase which contains (A) Ca++ (B) Fe++ (C) Zn++ (D) Mg++
Description : Select the option which is not correct with respect to enzyme action. (a) Substrate binds with enzyme at its active site. (b) Addition of lot of succinate does not reverse the inhibition ... from that which binds the substrate. (d) Malonate is a competitive inhibitor of succinic dehydrogenase.
Last Answer : (b) Addition of lot of succinate does not reverse the inhibition of succinic dehydrogenase by malonate.
Description : The number of ATP produced in the succinate dehydrogenase step is (A) 1 (B) 2 (C) 3 (D) 4
Description : An example of ligases is (A) Succinate thiokinase (B) Alanine racemase (C) Fumarase (D) Aldolase
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 : The metabolism of protein is integrated with that of carbohydrate and fat through (A) Oxaloacetate (B) Citrate (C) Isocitrate (D) Malate
Description : Which of these statements is incorrect? (a) Enzymes of TCA cycle are present in mitochondrial matrix. (b) Glycolysis occurs in cytosol. (c) Glycolysis operates as long as it is supplied ... that can pick up hydrogen atoms. (d) Oxidative phosphorylation takes place in outer mitochondrial membrane
Last Answer : (d) Oxidative phosphorylation takes place in outer mitochondrial membrane
Description : Why the bacterium Treponemapallidum is difficult to culture? A-.Because it requires a great deal of water to reproduce B- .Because it is unable to use carbohydrates as an energy source ... TCA cycle and oxidative phosphorylation D- Because it requires extremely low temperature at which water freezes
Last Answer : Because it lacks the genes needed for TCA cycle and oxidative phosphorylation
Description : Which of these statements is incorrect ? (1) Enzymes of TCA cycle are present in mitochondrial matrix. (2) Glycolysis occurs in cytosol. (3) Glycolysis operates as long as it is supplied ... that can pick up hydrogen atoms. (4) Oxidative phosphorylation takes place in outer mitochondrial membrane.
Last Answer : (4) Oxidative phosphorylation takes place in outer mitochondrial membrane.
Description : Substrate-linked phosphorylation occurs in (A) Glycolytic pathway(B) Citric acid cycle (C) Both (A) and (B) (D) None of these
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 : 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 : Two examples of substrate level phosphorylation in EM pathway of glucose metabolism are in the reactions of (A) 1,3 bisphosphoglycerate and phosphoenol pyruvate (B) Glucose-6 phosphate ... phosphate (C) 3 phosphoglyceraldehyde and phosphoenolpyruvate (D) 1,3 diphosphoglycerate and 2-phosphoglycerate
Last Answer : A
Description : Isocitrate dehydrogenases is (A) Aerobic dehydrogenase (B) Anaerobic dehydrogenase (C) Hydroperoxidase (D) Oxygenase
Description : An important zinc containing enzyme is (A) Carboxypeptidase A (B) Isocitrate dehydrogenase (C) Cholinesterate (D) Lipoprotein lipase
Description : Isocitrate dehydrogenase can use __________ as a cofactor. (A) NAD+ only (B) NADP+ only (C) NAD+ or NADP+ (D) FMN and FAD
Description : Isocitrate dehydrogenase is allosterically inhibited by (A) Oxalosuccinate (B) α-Ketoglutarate (C) ATP (D) NADH
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 : Zinc is a constituent of the enzyme: (A) Succinate dehydrogenase (B) Carbonic anhydrase (C) Mitochondrial superoxide dismutase (D) Aldolase
Description : Transfer of reducing equivalents from succinate dehydrogenase to coenzyme Q is specifically inhibited by (A) Carboxin (B) Oligomycin (C) Piericidin A (D) Rotenone
Description : A specific inhibitor for succinate dehydrogenase is (A) Arsenite (B) Malonate (C) Citrate (D) Fluoride