Description : Essential fructosuria is characterized by the lack of the hepatic enzyme: (A) Phosphohexose isomerase (B) Aldalose A (C) Aldolase B (D) Fructokinase
Last Answer : Answer : D
Description : Which of the following is an allosteric enzyme? (A) Phosphohexose isomerase (B) Phosphotriose isomerase (C) Lactate dehydrogenase (D) Phosphofructokinase
Description : In glycolytic pathway, iodacetate inhibits the activity of the enzyme: (A) Phosphotriose isomerase (B) Glyceraldehyde-3-phosphate dehydrogenase (C) Pyruvate kinase (D) Phosphofructokinase
Last Answer : Answer : B
Description : One of the enzymes regulating glycolysis is (A) Phosphofructokinase (B) Glyceraldehyde-3-phosphate dehydrogenase (C) Phosphotriose isomerase (D) Phosphohexose isomerase
Last Answer : Answer : A
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 : Conversion of fructose to sorbitol is catalysed by the enzyme: (A) Sorbitol dehydrogenase (B) Aldose reductase (C) Fructokinase (D) Hexokinase
Description : During glycolysis, Fructose 1, 6 diphosphate is decomposed by the enzyme: (A) Enolase a (B) Fructokinase (C) Aldolase (D) Diphosphofructophosphatose
Last Answer : C
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 : Fructose 2, 3 bi phosphate is a powerful allosteric activator of (A) Fructose 1, 6 diphosphatase (B) Phosphofructokinase (C) Hexokinase (D) Fructokinase
Description : A specific fructokinase present in liver has a very high affinity for its substrate because (A) Km for fructose is very high (B) Km for fructose is very low (C) Activity is affected by fasting (D) Activity is affected by insulin
Description : The 4 rate limiting enzymes of gluconeogenesis are (A) Glucokinase, Pyruvate carboxylae phosphoenol pyruvate carboxykinase and glucose-6-phosphatase (B) Pyruvate carboxylase, phosphoenol ... fructokinase, pyruvate carboxylase, phosphoenol pyruvate carboxykinase and fructose 1, 6 diphosphatase
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 fructose intolerance?
Last Answer : Due defective aldolase-B, fructose-1-phosphate accumulates. This leads to accumulation of glycogen in liver, and hypoglycemia.
Description : Insulin has no effect on the activity of the enzyme: (A) Glycogen synthetase (B) Fructokinase (C) Pyruvate kinase (D) Pyruvate dehydrogenase
Description : Lesch-Nyhan syndrome, the sex linked, recessive absence of HGPRTase, may lead to (A) Compulsive self destructive behaviour with elevated levels of urate in serum (B) Hypouricemia due to liver damage (C) Failure to thrive and megaloblastic anemia (D) Protein intolerance and hepatic encephalopathy
Description : Which of the following suggests a diagnosis of familial combined hyperlipidaemia (FCHL) rather than heterozygous familial hypercholesterolaemia (FH)? 1) Tendon xanthomas 2) Presence of glucose ... premature coronary artery disease 4) Presence of arcus senilus 5) Absence of hyperuricaemia
Last Answer : Answers-2 The genetic dislipidaemias occur in one third of patients who have suffered from their first myocardial infarction below the age of 50 years in men. The commonest is familial combined ... xanthomata and arcus cornea are rarely present in children, but are very important signs to identify.
Description : Glycerol is converted into glycerol-3- phosphate by (A) Thiokinase (B) Triokinase (C) Glycerol kinase (D) All of these
Last Answer : Answer : C
Description : Conversion of testosterone to estradiol requires the enzyme: (A) Aromatase (B) Dehydrogenase (C) Lyase (D) Isomerase HORMONE METABOLISM 215
Description : The enzyme catalyzing conversion of androstenedione to testosterone is a (A) Oxygenase (B) Dehydrogenase (C) Isomerase (D) Decarboxylase
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 : 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 : Alkaptonuria occurs due to deficiency of the enzyme: (A) Maleylacetoacetate isomerase (B) Homogentisate oxidase (C) p-Hydroxyphenylpyruvate hydroxylase (D) Fumarylacetoacetate hydrolase
Description : Albinism is a congenital disorder resulting from the lack of which enzyme? (a) Tyrosinase (b) Xanthine oxidase (c) Catalase (d) Fructokinase
Last Answer : (a) Tyrosinase
Description : The other name of invertase enzyme is A- sucrose B- saccharase C- isomerase D- both (a) and (b
Last Answer : both (a) and (b)
Description : Hexokinase has a high affinity for glucose than (A) Fructokinase (B) Galactokinase (C) Glucokinase (D) All of the above
Description : Glycogen synthetase activity is depressed by (A) Glucose (B) Insulin (C) Cyclic AMP (D) Fructokinase
Description : Fructokinase catalyses which reaction?
Last Answer : Fructose to fructose-1-phosphate.
Description : What is the importance of phospho fructokinase?
Last Answer : It is the key enzyme (rate limiting enzyme) of the pathway. It is an irreversible reaction.
Description : A substrate for the enzyme aldolase is (A) galactose-6-phosphate (B) isocitric acid (C) Glucose-1-phosphate (D) Fructose 1, 6 diphosphate
Description : Absence of the enzyme argininosuccinate synthetase causes (A) Argininosuccinic aciduria (B) Hyperargininemia (C) Tricorrhexis nodosa (D) Citrullinemia
Description : Amylopectinosis is caused due to absence of (A) Debranching enzyme (B) Branching enzyme (C) Acid maltase (D) Glucose-6-phosphatase
Description : Mc Ardle’s syndrome is characterized by the absence of (A) Liver phosphorylase (B) Muscle phosphorylase (C) Branching enzyme (D) Debranching enzyme
Description : Cori disease (Limit dextrinosis) is caused due to absence of (A) Branching enzyme (B) Debranching enzyme (C) Glycogen synthase (D) Phosphorylase
Description : The α-ketoacid is decarboxylated by H2O2 forming a carboxylic acid with one carbon atom less in the absence of the enzyme: (A) Catalase (B) Decarboxylase (C) Deaminase (D) Phosphatase
Description : Galactosemia is due the absence of which enzyme?
Last Answer : Galactose-1-phosphate uridyl transferase.
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 : 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 : Urease is a (A) Lyase (B) Ligase (C) Isomerase (D) Hydrolase
Description : Pyruvate dehydrogenase is a/an (A) Isomerase (B) Lyase (C) Ligase (D) Oxido reductase
Description : Glucose-6-phosphate is an allosteric inhibitor of (A) Glucokinase (B) Hexokinase (C) Phosphohexose isomerase (D) None of these
Description : Two molecules of acetyl-CoA condense to form acetoacetyl-CoA catalysed by (A) Thiolase (B) Kinase (C) Reductase (D) Isomerase
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
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 : The following are true about the oxidation of glucose: a. glycolysis produces 3% of the energy ultimately obtained from glucose b. the first stage of glycolysis involves phosphorylation of glucose to 1,6-fructose biphosphate. c. glucose enters the Kreb's cycle as pyruvate d. all above
Last Answer : all above
Description : Which one of the following regulatory actions involves a reversible covalent modification of the enzyme? (A) Phosphorylation of ser-OH on the enzyme (B) Allosteric modulation (C) Competitive inhibition (D) Non-competitive inhibition