In the synthetic pathway of epinephrine, disulfiram (antabuse) inhibits the enzyme: (A) Tyrosine hydroxylase (B) Dopamine β-hydroxylase (C) DOPA decarboxylase (D) N-methyl transferase

1 Answer

Answer :

Answer :  B

Related questions

Description : The rate limiting enzyme in the synthesis of catecholamines is: A. Tyrosine hydroxylase B. Dopa decarboxylase C. Dopamine β-hydroxylase D. Noradrenaline N-methyl transferase

Last Answer : A. Tyrosine hydroxylase

Description : The rate limiting enzyme in the synthesis of catecholamines is: A. Tyrosine hydroxylase B. Dopa decarboxylase C. Dopamine β-hydroxylase D. Noradrenaline N-methyl transferase

Last Answer : A. Tyrosine hydroxylase

Description : For Catecholamine biosynthesis the rate limiting enzyme is (A) DOPA decarboxylase (B) DOPAMINE β-hydroxylase (C) Tyrosine hydroxylase (D) Phenylalanine hydroxylase

Last Answer : Answer : C

Description : The rate limiting step in catecholamine synthesis is catalysed by (A) Phenylalanine hydroxylase (B) Tyrosine hydroxylase (C) Dopa decarboxylase (D) Phenylethanolamine N-methyl transferase

Last Answer : Answer : B

Description : The biosynthesis of both Catecholamine and serotonin require (A) Tyrosine hydroxylase (B) N-methyl transferase (C) Aromatic amino acid decarboxylase (D) Tryptophan pyrrolase

Last Answer : Answer : B

Description : The following enzymes on the left are responsible for the synthesis of the neurotransmitters on the right: a. monoamine oxidase: noradrenaline b. cholinesterase: acetylcholine c. catechol-o-methyl transferase: dopamine d. dopa decarboxylase: adrenaline

Last Answer : dopa decarboxylase: adrenaline

Description : Methyldopa lowers BP by: A. Inhibiting dopa decarboxylase in adrenergic nerve endings B. Generating α-methyl noradrenaline in brain which reduces sympathetic tone C. Generating α-methyl ... as a false transmitter in peripheral adrenergic nerve endings D. Activating vascular dopamine receptors

Last Answer : B. Generating α-methyl noradrenaline in brain which reduces sympathetic tone

Description : An inborn error, maple syrup urine disease is due to deficiency of the enzyme: (A) Isovaleryl-CoAhydrogenase (B) Phenylalnine hydroxylase (C) Adenosyl transferase (D) α-Ketoacid decarboxylase

Last Answer : Answer : D

Description : Dopa decarboxylase is inhibited by (A) Epinephrine (B) Norepinephrine (C) α−Methyldopa (D) None of these

Last Answer : Answer : C

Description : Immediate precursor of epinephrine is (A) Metanephrine (B) Norepinephrine (C) Dopa (D) Dopamine

Last Answer : Answer : B

Description : Blood brain barrier can be crossed by (A) Epinephrine (B) Dopamine (C) Dopa (D) All of these

Last Answer : Answer : C

Description : An enzyme involved in catabolism of catecholamines is (A) Dopa decarboxylase (B) Aromatic amino acid decarboxylase (C) Monoamine oxidase (D) Catechol oxidas

Last Answer : Answer : C

Description : Following events occur in the cytoplasm and not inside storage vesicles, except (a) Conversion of tyrosine to dopa (b) Conversion of dopa to dopamine (c) Conversion of dopamine to norepinephrine (d) Conversion of dopamine to 3,4 dihydroxy phenyl acetic acid

Last Answer : Ans: C

Description : β-Carotene, precursor of vitamin A, is oxidatively cleaved by (A) β-Carotene dioxygenase (B) Oxygenase (C) Hydroxylase (D) Transferase

Last Answer : Answer : A

Description : Biotin is a coenzyme of the enzyme (A) Carboxylase (B) Hydroxylase (C) Decarboxylase (D) Deaminase

Last Answer : Answer : A

Description : Vitamin K is involved in posttranslational modification of the blood clotting factors by acting as cofactor for the enzyme: (A) Carboxylase (B) Decarboxylase (C) Hydroxylase (D) Oxidase

Last Answer : Answer : A

Description : Orotic aciduria type II reflects the deficiency of the enzyme: (A) Orotate phosphoribosyl transferase (B) Orotidylate decarboxylase (C) Dihydroorotase (D) Dihydroorotate dehydrogenase

Last Answer : Answer : B

Description : A deficiency of copper effects the formation of normal collagen by reducing the activity of which of the following enzyme? (A) Prolyl hydroxylase (B) Lysyl oxidase (C) Lysyl hydroxylase (D) Glucosyl transferase

Last Answer : Answer : B

Description : β-Carotene, precursor of vitamin A, is oxidatively cleaved by (A) β-Carotene dioxygenase (B) Oxygenase \ (C) Hydroxylase (D) Transferase

Last Answer : (A) β-Carotene dioxygenase

Description : Selenium is a constituent of the enzyme: (A) Glutathione peroxidase (B) Homogentisate oxidase (C) Tyrosine hydroxylase (D) Phenylalanin hydroxylase

Last Answer : Answer : A

Description : The deficiency of copper decreases the activity of the enzyme: (A) Lysine oxidase (B) Lysine hydroxylase (C) Tyrosine oxidase (D) Proline hydroxylase

Last Answer : Answer : A

Description : Neonatal tyrosinemia is due to deficiency of the enzyme: (A) p-Hydroxyphenylpyruvate hydroxylase (B) Fumarylacetoacetate hydrolase (C) Phenylalanine hydroxylase (D) Tyrosine dehydrogenase

Last Answer : Answer : B

Description : Albinism is due to deficiency of the enzyme: (A) Phenylalanine hydroxylase (B) Tyrosinase (C) p-Hydroxyphenylpyruvic acid oxidase (D) Tyrosine dehydrogenase

Last Answer : Answer : C

Description : Tyrosinosis is due to defect in the enzyme: (A) Fumarylacetoacetate hydrolase (B) p-Hydroxyphenylpyruvate hydroxylase (C) Tyrosine transaminase (D) Tyrosine hydroxylase

Last Answer : Answer : A

Description : Biotin is a coenzyme of the enzyme (A) Carboxylase (B) Hydroxylase (C) Decarboxylase (D) Deaminase

Last Answer : (A) Carboxylase

Description : Vitamin K is involved in posttranslational modification of the blood clotting factors by acting as cofactor for the enzyme (A) Carboxylase (B) Decarboxylase (C) Hydroxylase (D) Oxidase

Last Answer : (A) Carboxylase

Description : Select the correct statement abut donepezil: A. It is a topical carbonic anhydrase inhibitor used in glaucoma B. It is a catechol-'O'-methyl transferase inhibitor used as adjuvant in ... affords symptomatic improvement in Alzheimer's disease D. It is a synthetic cannabinoid with antiemetic property

Last Answer : C. It is a cerebroselective anticholinesterase that affords symptomatic improvement in Alzheimer's diseas

Description : The enzyme dopamine β-oxidase which catalyses conversion of dopamine to norepinephrine requires (A) Vitamin A (B) Vitamin C (C) Vitamin E (D) Vitamin B12

Last Answer : Answer : B

Description : The sequential steps in the conversion of tyrosine to epinephrine are (A) Ring hydroxylation-decarboxylation-side chain hydroxylation-N-methylation (B) Side chain hydroxylation-decarboxylation- ... chain hydroxylation-N-methylation (D) N-methylation-decarboxylation-ring and side chain hydroxylation

Last Answer : Answer : A

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 : Formation of melanin from tyrosine requires the action of (A) Dopa decarboxylation (B) Diamine oxidase (C) Peroxidase (D) Tyrosinase

Last Answer : Answer : D

Description : Phenylalanine is the precursor of (A) L-DOPA (B) Histamine (C) Tyrosine (D) Throxine

Last Answer : C

Description : Increased urinary excretion of orotic acid can occur in deficiency of (A) Orotate phosphoribosyl transferase (B) OMP decarboxylase (C) Mitochondrial ornithine transcarbamoylase (D) Any of the above

Last Answer : Answer : D

Description : Orotic aciduria type I reflects the deficiency of enzymes: (A) Orotate phosphoribosyl transferase and orotidylate decarboxylase (B) Dihydroorotate dehydrogenase (C) Dihydroorotase (D) Carbamoyl phosphate synthetase

Last Answer : Answer : A

Description : Epinephrine is rapidly metabolized by (A) Monoamine oxidase (B) Deaminase (C) Transminase (D) Decarboxylase

Last Answer : Answer : A

Description : Tyrosine hydroxylase is inhibited by (A) Catecholamines (B) α−Methyldopa (C) Phenylalanine (D) Vanillyl mandelic acid

Last Answer : Answer : A

Description : Richner-Hanhart syndrome is due to defect in (A) Tyrosinase (B) Phenylalanine hydroxylase (C) Hepatic tyrosine transaminase (D) Fumarylacetoacetate hydrolase

Last Answer : Answer : B

Description : All the following statements about albinism are correct except (A) Tyrosine hydroxylase (tyrosinase) is absent or deficient in melanocytes (B) Skin is hypopigmented (C) It results in mental retardation (D) Eyes are hypopigmented

Last Answer : Answer : C

Description : Conversion of tyrosine to dihydroxyphenylalanine is catalysed by tyrosine hydroxylase which requires (A) NAD (B) FAD (C) ATP (D) Tetrahydrobiopterin

Last Answer : Answer : D

Description : Methyl dopa decreases blood pressure by (A) Inhibiting the synthesis of catecholamines (B) Antagonising the action of aldosterone (C) Stimulating the release of renin (D) Inhibiting the breakdown of angiotensin

Last Answer : Answer : A

Description : Dopamine is synthesised from (A) Dihydroxyphenylalanine (B) Epinephrine (C) Norepinephrine (D) Metanephrine

Last Answer : Answer : A

Description : ω-oxidation is normally a very minor pathway and is brought by hydroxylase enzymes involving (A) Cytochrome a (B) Cytochrome b (C) Cytochrome c (D) Cytochrome p-450

Last Answer : Answer : C

Description : A characteristic of pheochromocytoma is elevated urinary excretion of (A) Dopamine (B) Tyrosine (C) Vinylmandelic acid (D) Phenylalanine

Last Answer : Answer : C

Description : The rate limiting step in the biosynthesis of catecholamines is (A) Decarboxylation of dihydroxyphenylalanine (B) Hydroxylation of phenylalanine (C) Hydroxylation of tyrosine (D) Oxidation of dopamine

Last Answer : Answer : C

Description : Enzymic deficiency in β-aminoisobutyric aciduria is (A) Adenosine deaminase (B) Xanthine oxidase (C) Orotidylate decarboxylase (D) Transaminase

Last Answer : 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

Last Answer : Answer : A

Description : Erythromycin binds to 50 S ribosomal sub unit and (A) Inhibits binding of amino acyl tRNA (B) Inhibits Peptidyl transferase activity (C) Inhibits translocation (D) Causes premature chain termination

Last Answer : Answer : C

Description : In prokaryotes, chloramphenicol (A) Causes premature release of the polypeptide chain (B) Causes misreading of the mRNA (C) Depolymerises DNA (D) Inhibits peptidyl transferase activity

Last Answer : Answer : A

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

Last Answer : Answer : D

Description : Which of the following is a specific inhibitor of the enzyme alcohol dehydrogenase and is useful in the treatment of methanol poisoning: A. Disulfiram B. Ethylene glycol C. Calcium leucovorin D. Fomepizole

Last Answer : D. Fomepizole