Description : Thyroperoxidase iodinates (A) Free tyrosine in thyroid gland (B) Tyrosine residues of thyroglobulin (C) Tyrosine residues of thyroxine binding globulin (D) Tyrosine residues of thyroxine binding prealbumin
Last Answer : Answer : B
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 : Protein bound iodine is _________ bound to protein. (A) Iodine (B) Thyroid hormones (C) Thyroxine (D) Tri iodo thyronine
Description : Thyroid hormones are present in blood (A) In free form (B) In association with thyroxine binding globulin (TBG) (C) In association with thyroxine binding prealbumin (TBPA) (D) Mainly in association with TBG, partly in free form and sometimes in association with TBPA also
Last Answer : Answer : D
Description : Thyroperoxidase enzyme contains (A) Heme (B) Copper (C) Zinc (D) Magnesium
Last Answer : Answer : A
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 : The enzyme amino acyl tRNA synthetase is involved in (A) Dissociation of discharged tRNA from 80S ribosome (B) Charging of tRNA with specific amino acids (C) Termination of protein synthesis (D) Nucleophilic attack on esterified carboxyl group of peptidyl tRNA
Description : The regulatory enzyme for haem synthesis is (A) ALA synthetase (B) haem synthetase (C) Both (A) and (B) (D) None of these
Description : Hyperargininemia, a defect in urea synthesis develops due to deficiency of the enzyme: (A) Ornithine transcarbamoylase (B) Argininosuccinase (C) Arginase (D) Argininosuccinate synthetase ENZYMES 157
Description : ntithyroid drugs exert the following action: A. Inhibit thyroxine synthesis B. Block the action of thyroxine on pituitary C. Block the action of TSH on thyroid D. Block the action of thyroxine on peripheral tissues
Last Answer : A. Inhibit thyroxine synthesis
Description : Antithyroid drugs exert the following action: A. Inhibit thyroxine synthesis B. Block the action of thyroxine on pituitary C. Block the action of TSH on thyroid D. Block the action of thyroxine on peripheral tissues
Last Answer : . Inhibit thyroxine synthesis
Description : DOPA is an intermediate in the synthesis of (A) Thyroid hormones (B) Catecholamines (C) Melanin (D) Catecholamines and melanin
Description : All the following statements about phenylketonuria are correct except (A) Phenylalanine cannot be converted into tyrosine (B) Urinary excretion of phenylpyruvate and phenyllactate is increased (C) It ... diet (D) It leads to decreased synthesis of thyroid hormones, catecholamines and melanin
Description : All the enzymes required for de novo synthesis of pyrimidine nucleotides are cytosolic except (A) Carbamoyl phosphate synthetase (B) Aspartate transcarbamoylase (C) Dihydro-orotase (D) Dihydro-orotate dehydrogenase
Description : Uridine diphosphate glucose (UDPG) is (A) Required for metabolism of galactose (B) Required for synthesis of glucuronic acid (C) A substrate for glycogen synthetase (D) All of the above
Last Answer : D
Description : Tyrosine is required for the synthesis of all of the following except (A) Melatonin (B) Epinephrine (C) Norepinephrine (D) Thyroxine 222 MCQs IN BIOCHEMISTRY
Description : Hormones (A) Act as coenzyme (B) Act as enzyme (C) Influence synthesis of enzymes (D) Belong to B-complex group
Last Answer : Answer : C
Description : Name the hormone which stimulates the synthesis and secretion of thyroid hormones from the thyroid gland.
Last Answer : Name the hormone which stimulates the synthesis and secretion of thyroid hormones from the thyroid gland.
Description : Calcitomica is antagonist to (A) Serotonin (B) Thyroxine (C) Tri iodo thyronine (D) Para thyroid hormone
Description : Which one of the following hormones is derived most completely from tyrosine? (A) Glucagon (B) Thyroxine (C) Insulin (D) Prostaglandins
Description : All the following statements about primary gout are true except (A) Its inheritance is X-linked recessive (B) It can be due to increased activity of PRPP synthetase (C) It can be ... activity of hypoxanthine guanine phosphoribosyl transferase (D) De novo synthesis of purines is increased in it
Description : De novo synthesis of pyrimidine nucleotides is regulated by (A) Carbamoyl phosphate synthetase (B) Aspartate transcarbamoylase (C) Both (A) and (B) (D) None of these
Description : The first reaction unique to purine nucleotide synthesis is catalysed by (A) PRPP synthetase (B) PRPP glutamyl amido transferase (C) Phosphoribosyl glycinamide synthetase (D) Formyl transferase
Description : All of the following enzymes are unique to purine nucleotide synthesis except (A) PRPP synthetase (B) PRPP glutamyl amido transferase (C) Adenylosuccinate synthetase (D) IMP dehydrogenase
Description : In the pathway of de novo synthesis of purine nucleotides, all the following are allosteric enzymes except (A) PRPP glutamyl amido transferase (B) Adenylosuccinate synthetase (C) IMP dehydrogenase (D) Adenylosuccinase
Description : Insulin decreases the synthesis of (A) Hexokinase (B) Glucokinase (C) PEP carboxykinase (D) Glycogen synthetase
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 : Cytosolic and mitochondrial carbamoyl phosphate synthetase have the following similarity: (A) Both use ammonia as a substance (B) Both provide carbamoyl phosphate for urea synthesis (C) Both require N-acetylglutamate as an activator (D) Both are allosteric enzymes
Description : TSH stimulates the synthesis delete (A) Thyroxine (B) Adrenocorticoids (C) Epinephrine (D) Insulin
Description : All the following statements about charging of tRNA are correct except (A) It is catalysed by amino acyl tRNA synthetase (B) ATP is converted into ADP and Pi in this reaction (C) The enzyme recognizes the tRNA and the amino acid (D) There is a separate enzyme for each tRNA
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 : Conversion of deoxyuridine monophosphate to thymidine monophosphate is catalysed by the enzyme: (A) Ribonucleotide reductase (B) Thymidylate synthetase (C) CTP synthetase (D) Orotidylic acid decarboxylase
Description : An enzyme which acts as allosteric regulator and sensitive to both phosphate concentration and to the purine nucleotides is (A) PRPP synthetase (B) PRPP glutamyl midotransferase (C) HGPR Tase (D) Formyl transferase
Description : The enzyme that converts glucose to glucose-6-phosphate is (A) Phosphatase (B) Hexokinase (C) Phosphorylase (D) Glucose synthetase
Description : Absence of the enzyme argininosuccinate synthetase causes (A) Argininosuccinic aciduria (B) Hyperargininemia (C) Tricorrhexis nodosa (D) Citrullinemia
Description : Enzyme deficient in Hyperammonemia type II is (A) Glutamine synthetase (B) Glutaminase (C) Ornithine transcarbamoylase (D) Carbamoylphosphate synthetase
Description : Jamaican vomiting sickness is due to inactivation of the enzyme (A) Pyruvate carboxylase (B) Acyl-Co-A synthetase (C) Acyl-Co-A dehydrogense (D) Thiolase
Description : In the biosynthesis of cholesterol, the rate limiting enzyme is (A) Mevalonate kinase (B) HMG-CoA synthetase (C) HMG-CoA reductase (D) Cis-prenyl transferase
Description : Carboxylation of acetyl-CoA to malonylCoA requires the enzyme: (A) Acetyl-CoA carboxylase (B) Pyruvate carboxylase (C) Acetyl transacylase (D) Acyl CoA-synthetase
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 : 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 : Enzyme involved in joining together two substrates is (A) Glutamine synthetase (B) Aldolase (C) Gunaine deaminase (D) Arginase
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 : The following enzyme of urea cycle is present in cytosol: (A) Argininosuccinic acid synthetase (B) Argininosuccinase (C) Arginase (D) All of these
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 : Control of urea cycle involves the enzyme: (A) Carbamoyl phosphate synthetase (B) Ornithine transcarbamoylase (C) Argininosuccinase (D) Arginase
Description : The enzyme carbamoyl phosphate synthetase requires (A) Mg++ (B) Ca++ (C) Na+ (D) K+
Description : The following are true: a. thyroxine is formed by iodination of tyrosine b. the ratio of T3 :T4 secreted by the thyroid gland is 1:5 c. about 99.5% of thyroxines is protein bound d. T3 is more active than T4
Last Answer : T3 is more active than T4
Description : The following are true about the thyroid hormone a. iodide ions enter the follicle cells by passive diffusion b .T4 and T3 bind to the receptors in nuclei c. thyroxine, once ... thyroglobulin until released d. a greater proportion of tri-iodothyronine is formed when iodine is deficient
Last Answer : T4 and T3 bind to the receptors in nuclei