Description : Urease is a (A) Lyase (B) Ligase (C) Isomerase (D) Hydrolase
Last Answer : Answer : D
Description : Conversion of testosterone to estradiol requires the enzyme: (A) Aromatase (B) Dehydrogenase (C) Lyase (D) Isomerase HORMONE METABOLISM 215
Last Answer : Answer : A
Description : In the biosynthesis of cortiol, the sequence of enzymes involved is (A) Hydroxylase–dehydrogenase + isomerase – hydroxylase (B) Dehydrogenase–hydroxylase–isomerase (C) Hydroxylase–lyase–dehydrogenase isomerase (D) Isomerase–lyase–hydroxylase–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 : 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
Last Answer : Answer : C
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
Last Answer : Answer : B
Description : In glycolytic pathway, iodacetate inhibits the activity of the enzyme: (A) Phosphotriose isomerase (B) Glyceraldehyde-3-phosphate dehydrogenase (C) Pyruvate kinase (D) Phosphofructokinase
Description : Insulin degradation of disulfide bond formation is effected by (A) Pyruvate dehydrogenase (B) Xylitol reductase (C) Gutathione reductase (D) Xanthine oxidase
Description : An enzyme required for the synthesis of ketone bodies as well as cholesterol is (A) Acetyl CoA carboxylase (B) HMG CoA synthetase (C) HMG CoA reductase (D) HMG CoA lyase
Description : In biosynthesis of cholesterol triparanol inhibits the activity of the enzyme: (A) ∆24 Reductase (B) Oxidosqualene-lanosterol cyclase (C) Isomerase (D) Squalene epoxidase ENZYMES 155
Description : Two molecules of acetyl-CoA condense to form acetoacetyl-CoA catalysed by (A) Thiolase (B) Kinase (C) Reductase (D) Isomerase
Description : The enzyme involved in essential pentosuria is (A) Reductase (B) Hydroxylase (C) Isomerase (D) Racemase
Description : Ceruloplasmin shows the activity (A) As ferroxidase (B) As reductase (C) As ligase (D) As transferase
Description : Activity of ceruloplasmin shown in vitro: (A) Reductase (B) Hydrolase (C) Ligase (D) Oxidase
Description : An enzyme involved in gluconeogenesis is (A) Pyruvate kinase (B) Pyruvate carboxylase (C) Hexokinase (D) Phosphohexose isomerase
Description : ATP is ‘wasted’ in Rapoport-Lueberring cycle in RBCs as otherwise it will inhibit (A) Phosphoglucomutase (B) Phosphohexo isomerase (C) Phosphofructo kinase (D) Phosphoenol pyruvate carboxy kinase
Last Answer : C
Description : The enzyme catalyzing conversion of androstenedione to testosterone is a (A) Oxygenase (B) Dehydrogenase (C) Isomerase (D) Decarboxylase
Description : 3-β-Hydroxysteroid dehydrogenase and ∆5,4 isomerase catalyse the conversion of the weak androgen DHEA to (A) Androstenedione (B) Testosterone (C) Progesterone (D) Estrone
Description : Which of the following is an allosteric enzyme? (A) Phosphohexose isomerase (B) Phosphotriose isomerase (C) Lactate dehydrogenase (D) Phosphofructokinase
Description : Hemolytic anemia is caused by the deficiency of certain enzymes of the pentose phosphate pathway, the principal enzyme involved is (A) Glucose-6-phosphate dehydrogenase (B) Aldolase (C) Fructose 1, 6-bisphosphatase (D) Phosphohexose isomerase
Description : One of the enzymes regulating glycolysis is (A) Phosphofructokinase (B) Glyceraldehyde-3-phosphate dehydrogenase (C) Phosphotriose isomerase (D) Phosphohexose isomerase
Description : Conversion of fructose to sorbitol is catalysed by the enzyme: (A) Sorbitol dehydrogenase (B) Aldose reductase (C) Fructokinase (D) Hexokinase
Description : FAD is a coenzyme for (A) Succinate dehydrogenase (B) Glycerol-3-phosphate dehydrogenase (C) Sphingosine reductase (D) All of these
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 : 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 : Thiamine is essential for (A) Pyruvate dehydrogenase (B) Isocitrate dehydrogenase (C) Succinate dehydrogenase (D) Acetyl CoA synthetase ENZYMES 165
Description : All the following are coenzymes except (A) Ubiquinone (B) CoA (C) Pyruvate dehydrogenase (D) Lipoic acid
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 : 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 : Pyruvate dehydrogenase complex is regulated by (A) Covalent modification (B) Allosteric regulation (C) Both (A) and (B) (D) None of these
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 : 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 : 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 : 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
Description : Lipoic acid is a conenzyme for (A) Pyruvate dehydrogenase (B) α-Ketoglutarate dehydrogenae (C) Both (A) and (B) (D) None of these
Description : NADPH is produced when this enzyme acts (A) Pyruvate dehydrogenase (B) Malic enzyme (C) Succinate dehydrogenase (D) Malate dehydrogenase
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
Last Answer : D
Description : The “Primaquin sensitivity types of haemolytic anaemia has been found to relate to reduced R.B.C activity of which enzyme? (A) Pyruvate kinase deficiency (B) Glucose-6-phosphatase deficiency (C) Glucose-6-p dehydrogenase deficiency (D) Hexokinase deficiency
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