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 : 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 : 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 : 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 : Malonate is an inhibitor of (A) Malate dehydrogenase (B) α-Ketoglutarate dehydrogenase (C) Succinate dehydrogenase (D) Isocitrate dehydrogenase
Description : In TCA cycle, oxalosuccinate is converted to α-ketoglutarate by the enzyme: (A) Fumarase (B) Isocitrate dehydrogenase (C) Aconitase (D) Succinase
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 : The reaction catalysed by α-ketoglutarate dehydrogenase in the citric acid cycle requires (A) NAD (B) NADP (C) ADP (D) ATP
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 : All of the following are allosteric enzymes except (A) Citrate synthetase (B) a-Ketoglutarate dehdrogenase (C) Succinate thiokinase (D) Succinate dehydrogenase
Description : The enzyme -ketoglutarate dehydrogenase in the citric acid cycle requires (A) Lipoate (B) Folate (C) Pyridoxine (D) Inositol
Description : The rate of citric acid cycle is controlled by the allosteric enzyme: (A) Aconitase (B) Fumarase (C) Fumarase (D) Malate dehydrogenase
Description : Isocitrate dehydrogenase is allosterically inhibited by (A) Oxalosuccinate (B) α-Ketoglutarate (C) ATP (D) NADH
Description : Among citric acid cycle enzymes, a flavoprotein is (A) Malate (B) Fumarase (C) Succinate dehrogenase (D) Isocitrate dehrogenase
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 : 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 : A carrier molecule in the citric acid cycle is (A) Acetyl-CoA (B) Citrate (C) Oxaloacetate (D) Malate
Description : A compound serving a link between citric acid cycle and urea cycle is (A) Malate (B) Citrate (C) Succinate (D) Fumarate
Description : A competitive inhibitor of succinic dehydrogenase is (a) α-ketoglutarate (b) malate (c) malonate (d) oxaloacetate.
Last Answer : (c) malonate
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 : 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 : The metabolism of protein is integrated with that of carbohydrate and fat through (A) Oxaloacetate (B) Citrate (C) Isocitrate (D) Malate
Description : The hexose monophosphate pathway includes the enzyme: (A) Maltase dehydrogenase (B) Hexokinase (C) α-Ketoglutarate dehydrogenase (D) Glucose-6-phosphate dehydrogenase
Description : Thiamine is essential for (A) Pyruvate dehydrogenase (B) Isocitrate dehydrogenase (C) Succinate dehydrogenase (D) Acetyl CoA synthetase ENZYMES 165
Description : Lipoic acid is a conenzyme for (A) Pyruvate dehydrogenase (B) α-Ketoglutarate dehydrogenae (C) Both (A) and (B) (D) None of these
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 : 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 : 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 : Mitochondrial α-ketoglutarate dehydrogenase complex requires all the following to function except (A) CoA (B) FAD (C) NAD+ (D) NADP+
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 carrier of the citric acid cycle is (A) Succinate (B) Fumarate (C) Malate (D) Oxaloacetate
Description : The integrator between the TCA cycle and urea cycle is (A) Fumarate (B) Malate (C) Pyruvate (D) Citrate
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 : 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 : Calcium is required for the activation of the enzyme: (A) Isocitrate dehydrogenase (B) Fumarase (C) Succinate thiokinase (D) ATPase
Description : An important zinc containing enzyme is (A) Carboxypeptidase A (B) Isocitrate dehydrogenase (C) Cholinesterate (D) Lipoprotein lipase
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 : An enzyme catalyzing oxidoreduction, using oxygen as hydrogen acceptor is (A) Cytochrome oxidase (B) Lactate dehydrogenase (C) Malate dehydrogenase (D) Succinate dehydrogenase
Description : NADPH is produced when this enzyme acts (A) Pyruvate dehydrogenase (B) Malic enzyme (C) Succinate dehydrogenase (D) Malate dehydrogenase
Description : For extramitochondrial fatty acid synthesis, acetyl CoA may be obtained from (A) Citrate (B) Isocitrate (C) Oxaloacetate (D) Succinate
Description : An enzyme in saliva which hydrolyzes starch is (A) Pepsinogen (B) Chymotrysin (C) α-Amylase (D) Malate
Description : In citric acid cycle, GDP is phosphorylated by (A) Succinate dehydrogenase (B) Aconitase (C) Succinate thiokinase (D) Fumarse
Description : An enzyme of pyrimidine nucleotides biosynthesis regulated at the genetic level by apparently coordinate repression and derepression is (A) Carbamoyl phosphate synthetase (B) Dihydroorotate dehydrogenase (C) Thymidine kinase (D) Deoxycytidine kinase
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 : Insulin has no effect on the activity of the enzyme: (A) Glycogen synthetase (B) Fructokinase (C) Pyruvate kinase (D) Pyruvate dehydrogenase
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 : 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 : With the exception of glycine all amino acids found in protein are (A) Isocitrate dehydrogenase (B) Fumarase (C) Succinate thiokinase (D) ATPase
Description : Citrate is converted to isocitrate by aconitase which contains (A) Ca++ (B) Fe++ (C) Zn++ (D) Mg++
Description : The following enzyme of urea cycle is present in cytosol: (A) Argininosuccinic acid synthetase (B) Argininosuccinase (C) Arginase (D) All of these