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 : Malonate is an inhibitor of (A) Malate dehydrogenase (B) α-Ketoglutarate dehydrogenase (C) Succinate dehydrogenase (D) Isocitrate dehydrogenase
Last Answer : Answer : C
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
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 : 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 : 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
Last Answer : Answer : D
Description : Formation of succinyl-CoA from α-Ketoglutarate is inhibited by (A) Fluoroacetate (B) Arsenite (C) Fluoride (D) Iodoacetate
Description : The hexose monophosphate pathway includes the enzyme: (A) Maltase dehydrogenase (B) Hexokinase (C) α-Ketoglutarate dehydrogenase (D) Glucose-6-phosphate dehydrogenase
Description : Lipoic acid is a conenzyme for (A) Pyruvate dehydrogenase (B) α-Ketoglutarate dehydrogenae (C) Both (A) and (B) (D) None of these
Description : Mitochondrial α-ketoglutarate dehydrogenase complex requires all the following to function except (A) CoA (B) FAD (C) NAD+ (D) NADP+
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 : All of the following statements about thioredoxin reductase are true except: (A) It requires NADH as a coenzyme (B) Its substrates are ADP, GDP, CDP and UDP (C) It is activated by ATP (D) It is inhibited by dADP
Description : PRPP synthetase is allosterically inhibited by (A) AMP (B) ADP (C) GMP (D) All of these
Description : Phosphofructokinase is allosterically inhibited by (A) Fructose-1, 6-biphosphate (B) Lactate (C) Pyruvate (D) Citrate
Description : An allosteric inhibitor of pyruvate dehydrogenase is (A) Acetyl CoA (B) ATP (C) NADH (D) Pyruvate
Description : A competitive inhibitor of succinic dehydrogenase is (a) α-ketoglutarate (b) malate (c) malonate (d) oxaloacetate.
Last Answer : (c) malonate
Description : Acyl-CoA dehydrogenase converts Acyl CoA to α-β unsaturated acyl-CoA in presence of the coenzyme: (A) NAD+ (B) NADP+ (C) ATP (D) FAD
Description : Calcium is required for the activation of the enzyme: (A) Isocitrate dehydrogenase (B) Fumarase (C) Succinate thiokinase (D) ATPase
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 : 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 : 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 : Substrate level phosphorylation in TCA cycle is in step: (A) Isocitrate dehydrogenase (B) Malate dehydrogenase (C) Aconitase (D) Succinate thiokinase
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 : 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 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 : 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 : 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 : 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 : Retinol and retinal are interconverted requiring dehydrogenase or reductase in the presence of (A) NAD or NADP (B) NADH + H+ (C) NADPH (D) FAD
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 : Pyruvate dehydrogenase activity is inhibited by (A) Mercury (B) Zinc (C) Calcium (D) Sodium
Description : Which of the following enzymes in Glycolytic pathway is inhibited by fluoride? (A) Glyceraldehyde-3-p dehydrogenase (B) Phosphoglycerate kinase (C) Pyruvate kinase (D) Enolase
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 : Coenzymes derived from the vitamin shown below are required by enzymes involved in the synthesis of which of the following? (A) ATP (B) UTP (C) CTP (D) NADH
Description : Which one of the following transfers acyl groups? (A) Thiamine pyrophosphate (B) Lipomide (C) ATP (D) NADH
Description : Oxidative degradation of acetyl CoA in the citric acid cycle gives a net yield of all the following except (A) FADH2 (B) 3 NADH (C) 2 ATP (D) 2CO2
Description : De novo synthesis of fatty acids requires all of the following except (A) Biotin (B) NADH (C) Panthothenic acid (D) ATP
Description : Aspartate transcarbamoylase is inhibited by (A) CTP (B) PRPP (C) ATP (D) TMP
Description : The enzyme aspartate transcarbamoylase of pyrimidine biosynthesis is inhibited by (A) ATP (B) ADP (C) AMP (D) CTP
Description : Phosphofructokinase key enzyme in glycolysis is inhibited by (A) Citrate and ATP (B) AMP (C) ADP (D) TMP
Description : The reaction catalysed by phosphofructokinase (A) Is activated by high concentrations of ATP and citrate (B) Uses fruitose-1-phosphate as substrate (C) Is the rate-limiting reaction of the glycolytic pathway (D) Is inhibited by fructose 2, 6-bisphosphate
Last Answer : C
Description : All of the following statements about the enzymic complex that carries out the synthesis of ATP during oxidative phosphorylation are correct except (A) It is located on the matrix side of the inner ... inhibited by oligomycin (C) It can exhibit ATPase activity (D) It can bind molecular O2
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