Description : Pyruvate dehydrogenase is a/an (A) Isomerase (B) Lyase (C) Ligase (D) Oxido reductase
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 : Alkaptonuria occurs due to deficiency of the enzyme: (A) Maleylacetoacetate isomerase (B) Homogentisate oxidase (C) p-Hydroxyphenylpyruvate hydroxylase (D) Fumarylacetoacetate hydrolase
Last Answer : Answer : B
Description : The enzyme hexokinase is a (A) Hydrolase (B) Oxidoreductase (C) Transferase (D) Ligase
Last Answer : Answer : C
Description : Activity of ceruloplasmin shown in vitro: (A) Reductase (B) Hydrolase (C) Ligase (D) Oxidase
Description : An enzyme common to de novo synthesis of pyrimidine nucleotides and urea is (A) Urease (B) Carbamoyl phosphate synthetase (C) Aspartate transcarbamoylase (D) Argininosuccinase
Description : In humans purine are catabolised to uric acid due to lack of the enzyme: (A) Urease (B) Uricase (C) Xanthine oxidase (D) Guanase
Description : The first enzyme isolated, purified and crystallied from Jack bean (Canavalia) by summer in 1926 was (A) Urease (B) Insulin (C) Ribonuclease (D) Zymase
Description : Urea is produced physiologically by the action of the enzyme: (A) Urease (B) Glutaminase (C) Arginase (D) None of these
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
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
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 : Give an example of lyase.
Last Answer : Aldolase.
Description : Which enzyme is concerned with transfer of electrons? (A) Desmolase (B) Hydrolase (C) Dehydrogenase (D) Transaminase
Description : In which of the following types of enzymes, water may be added to a C—C double bond without breaking the bond? (A) Hydrolase (B) Hydratase (C) Hydroxylase (D) Oxygenase
Description : In which of the following types of enzyme water may be added to a C—C double bond without breaking the bond? (A) Hydrolase (B) Hydratase (C) Hydroxylase (D) Esterase
Description : The decarboxylation reaction in HMP shunt is catalysed by (A) Gluconolactone hydrolase (B) 6-Phosphogluconate dehydrogenase (C) 6-Phosphogluconate decarboxylase (D) Transaldolase
Description : Neonatal tyrosinemia is due to deficiency of the enzyme: (A) p-Hydroxyphenylpyruvate hydroxylase (B) Fumarylacetoacetate hydrolase (C) Phenylalanine hydroxylase (D) Tyrosine dehydrogenase
Description : Wolman’s disease is due to deficiency of (A) Cholesteryl ester hydrolase (B) Hexosaminidase A (C) α-Fucosidase (D) Arylsulphatase A
Description : The enzyme which can add water to a carbon-carbon double bond or remove water to create a double bond without breaking the bond is (A) Hydratase (B) Hydroxylase (C) Hydrolase (D) Esterase
Description : Pancreatic lipose is an enzyme which hydrolyzes facts. It acts as a/an (A) peptidase (B) hydrolase (C) carbohydrates (D) dehydrogenase
Description : Tyrosinosis is due to defect in the enzyme: (A) Fumarylacetoacetate hydrolase (B) p-Hydroxyphenylpyruvate hydroxylase (C) Tyrosine transaminase (D) Tyrosine hydroxylase
Description : Richner-Hanhart syndrome is due to defect in (A) Tyrosinase (B) Phenylalanine hydroxylase (C) Hepatic tyrosine transaminase (D) Fumarylacetoacetate hydrolase
Description : Transfer of the carbamoyl moiety of carbamoyl phosphate to ornithine is catalysed by a liver mitochondrial enzyme: (A) Carbamoyl phosphate synthetase (B) Ornithine transcarbamoylase (C) N-acetyl glutamate synthetase (D) N-acetyl glutamate hydrolase
Description : In abetalipoproteinemia, the biochemical defect is in (A) Apo-B synthesis (B) Lipprotein lipase activity (C) Cholesterol ester hydrolase (D) LCAT activity
Description : Give an example of a hydrolase.
Last Answer : Acetyl choline esterase.
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 : Glucose-6-phosphate is an allosteric inhibitor of (A) Glucokinase (B) Hexokinase (C) Phosphohexose isomerase (D) None of these
Description : Which of the following is an allosteric enzyme? (A) Phosphohexose isomerase (B) Phosphotriose isomerase (C) Lactate dehydrogenase (D) Phosphofructokinase
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 : Essential fructosuria is characterized by the lack of the hepatic enzyme: (A) Phosphohexose isomerase (B) Aldalose A (C) Aldolase B (D) Fructokinase
Description : Hereditary fructose intolerance involves the absence of the enzyme: (A) Aldalose B (B) Fructokinase (C) Triokinase (D) Phosphotriose isomerase
Description : The enzyme involved in essential pentosuria is (A) Reductase (B) Hydroxylase (C) Isomerase (D) Racemase
Description : An enzyme involved in gluconeogenesis is (A) Pyruvate kinase (B) Pyruvate carboxylase (C) Hexokinase (D) Phosphohexose isomerase
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 : In glycolytic pathway, iodacetate inhibits the activity of the enzyme: (A) Phosphotriose isomerase (B) Glyceraldehyde-3-phosphate dehydrogenase (C) Pyruvate kinase (D) Phosphofructokinase
Description : From arachidonate, synthesis of prostaglandins is catalysed by (A) Cyclooxygenase (B) Lipoxygenase (C) Thromboxane synthase (D) Isomerase
Description : Retinol isomerase is present in (A) Retina (B) Liver (C) Both (A) and (B) (D) None of these
Description : Folding of newly synthesized proteins is accelerated by (A) Protein disulphide isomerase (B) Prolyl cis-trans isomerase (C) Chaperonins (D) All of these
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 : Dihydroxyacetone phosphate and glyceraldehyde-3-phosphate are intercoverted by CARBOHYDRATES AND CARBOHYDRATE METABOLISM 13 (A) Triose isomerase (B) Phosphotriose isomerase (C) Diphosphotriose isomerase (D) Dihydroxyacetone phosphorylase
Last Answer : B
Description : Fructose-2, 6-biphosphate is formed by the action of (A) Phosphofructokinase-1 (B) Phosphofructokinase-2 (C) Fructose biphosphate isomerase (D) Fructose-1, 6-biphosphatase
Description : What is the function of isomerase?
Last Answer : Isomerase shifts the ester bond from position 2 to 1, this is then hydrolysed by the lipase to form free glycerol and fatty acid.
Description : Give an example of isomerase.
Last Answer : Triose phosphate isomerase.
Description : J. B. Sumner isolated first enzyme from Jackbeans as- (1) amylase (2) trypsin (3) urease (4) renin
Last Answer : (3) urease Explanation: James Batcheller Sumner (November 19, 1887 – August 12, 1955) was an American chemist. He discovered that enzymes can be crystallized.