The following are true about the neurotransmitters:
a. acetylcholine is inactivated mainly by presynaptic reuptake
b. tyrosine is essential for the formation of dopamine
c. noradrenaline is inactivated mainly by hydrolysis
d. adrenaline is formed from methylation of the noradrenaline

1 Answer

Answer :

adrenaline is formed from methylation of the noradrenaline

Related questions

Description : True statements about the following neurotransmitters include: a. dopamine is formed from tyrosine b. in the synapse, noradrenaline is inactivated by active reuptake into the presynpatic terminals c. noradrenaline is formed by hydroxylation of dopamine d. all above

Last Answer : all above

Description : The following are true about acetylcholine: a. it is synthesized from acetyl-coenzyme A and choline b. its formation is catalysed by acetylcholinesterase c. at the synaptic cleft, ... inactivated by hydrolysis d. reuptake by the presynaptic neurones play an important in inactivating acetylcholine

Last Answer : at the synaptic cleft, it is inactivated by hydrolysis

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 : The following are true: a. heroin causes miosis by increasing the release of acetylcholine. b. botulinum toxin causes mydriasis by inhibiting the release of acetylcholine c. ... mydriasis by stimulating the alpha receptors d. amphetamine causes mydriasis by inhibiting noradrenaline reuptake

Last Answer : phenylephrine causes mydriasis by stimulating the alpha receptors

Description : The following is true of bupropion except: A. It inhibits dopamine reuptake along with inhibiting noradrenaline reuptake B. It produces sedation as a side effect C. It is being used as an aid for smoking cessation D. It is likely to produce seizures in overdose

Last Answer : B. It produces sedation as a side effect

Description : The following are neurotransmitters in the autonomic ganglia: a. GABA b. noradrenaline c. acetylcholine d. 5 HT

Last Answer : acetylcholine

Description : The following are neurotransmitters at the autonomic post-ganglionic nerve endings: a. GABA b. noradrenaline c. acetylcholine d. 5 HT

Last Answer : acetylcholine

Description : At the adrenergic synapse, the concentration of adrenaline in synaptic cleft: a. increased by cocaine which inhibit reuptake of adrenaline b. decreased by MAO (monoamine oxidase) - inhibitors c. controlled chiefly by the activity of the enzyme COMT d. increased by noradrenaline receptor blockers

Last Answer : increased by cocaine which inhibit reuptake of adrenaline

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 : Which of the following is labelled as a 'serotonin and noradrenaline reuptake inhibitor or SNRI': A. Amineptine B. Venlafaxine C. Bupropion D. Citalopram

Last Answer : D. Citalopram

Description : Venlafaxine differs from standard tricyclic antidepressants in that it: A. Does not inhibit 5-HT reuptake B. Does not inhibit noradrenaline reuptake C. Does not have anticholinergic or antiadrenergic property D. Has lower antidepressant efficacy

Last Answer : C. Does not have anticholinergic or antiadrenergic property

Description : Adaptive changes in brain monoamine turnover due to blockade of noradrenaline/5-HT reuptake is credited with the following effect: A. Antipsychotic B. Antianxiety C. Antiparkinsonian D. Antidepressant

Last Answer : D. Antidepressant

Description : The principal process which terminates the action of noradrenaline released from adrenergic nerve ending is: A. Degradation by MAO B. Methylation by COMT C. Axonal uptake D. Extraneuronal uptake

Last Answer : C. Axonal uptake

Description : The principal process which terminates the action of noradrenaline released from adrenergic nerve ending is: A. Degradation by MAO B. Methylation by COMT C. Axonal uptake D. Extraneuronal uptake

Last Answer : C. Axonal uptake

Description : The primary action by which entacapone and tolcapone enhance the therapeutic effect of levodopa-carbidopa in parkinsonism is: A. Inhibition of levodopa methylation in the liver B. Inhibition of ... of dopamine in the brain D. Facilitation of active transport of levodopa across brain capillaries

Last Answer : A. Inhibition of levodopa methylation in the liver

Description : Hormones thyroxine, adrenaline and the pigment melanin are formed from (a) tyrosine (b) proline (c) tryptophan (d) glycine.

Last Answer : (a) tyrosine

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 : The mechanisms involved in the causation of dangerous cardiac arrhythmias due to overdose of tricyclic antidepressants include the following except: A. Intraventricular conduction block B. Potentiation of noradrenaline C. Antagonism of acetylcholine D. Increased vagal tone

Last Answer : D. Increased vagal tone

Description : The neurotransmitter agent that is normally released in the sinoatrial node of the heart in response to a blood pressure increase is (a) Acetylcholine (b) Dopamine (c) Epinephrine (d) Glutamate (e) Norepinephrine

Last Answer : Ans: A

Description : Nicotine acts as a stimulant, because it mimics the effect of (a) testosterone (b) dopamine (c) thyroxine (d) acetylcholine.

Last Answer : (d) acetylcholine.

Description : Parkinson’s disease (characterized by tremors and progressive rigidity of limbs) is caused by degeneration of brain neurons that are involved in movement control and make use of neurotransmitter (a) acetylcholine (b) norepinephrine (c) dopamine (d) GABA.

Last Answer : c) dopamine

Description : Alzheimer’s disease in humans is associated with the deficiency of (a) glutamic acid (b) acetylcholine (c) gamma aminobutyric acid (GABA) (d) dopamine.

Last Answer : b) acetylcholine

Description : Myasthenia Gravis is characterized by Options: 1) Decrease in acetylcholine reserve in motor nerve terminal 2) Decrease in dopamine reserve in motor nerve terminal 3) Decrease in receptors for acetylcholine 4) Decrease in dopamine receptors

Last Answer : Correct Answer: 3) Decrease in receptors for acetylcholine

Description : Select the prokinetic-antiemetic drug which at relatively higher doses blocks both dopamine D2 as well as 5-HT3 receptors and enhances acetylcholine release from myenteric neurones: A. Cisapride B. Prochlorperazine C. Metoclopramide D. Domperidon

Last Answer : C. Metoclopramide

Description : A sympathomimetic amine that acts almost exclusively by releasing noradrenaline from the nerve endings is (a) Ephedrine (b) Dopamine (c) Isoprenaline (d) Tyramine

Last Answer : Ans: D

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 : A sympathomimetic amine that acts almost exclusively by releasing noradrenaline from the nerve endings is: A. Ephedrine B. Dopamine C. Isoprenaline D. Tyramine

Last Answer : D. Tyramine

Description : The following biogenic amine is not actively taken up into its storage site by an active amine pump: A. Histamine B. 5-Hydroxy tryptamine C. Dopamine D. Noradrenaline

Last Answer : A. Histamine

Description : A sympathomimetic amine that acts almost exclusively by releasing noradrenaline from the nerve endings is: A. Ephedrine B. Dopamine C. Isoprenaline D. Tyramine

Last Answer : D. Tyramine

Description : The muscle fatigue occurs due to the release of (a) acetylcholine (b) lactic acid (c) adrenaline (d) none of these

Last Answer : Ans:(b)

Description : The secretion of insulin is stimulated by: a. adrenaline b. somatostatin c. fatty acids d. acetylcholine

Last Answer : fatty acids

Description : Tyrosine kinase activity is present in (A) Acetylcholine receptor (B) PDGF receptor (C) ADH receptor (D) All of these

Last Answer : Answer : B

Description : Adrenaline and noradrenaline are called hormones. Why?

Last Answer : Adrenaline and noradrenaline are called hormones. Why?

Description : Compared to a bull a bullock is docile because of (a) higher levels of cortisone (b) lower levels of blood testosterone (c) lower levels of adrenaline/noradrenaline in its blood (d) higher levels of thyroxine.

Last Answer : (b) lower levels of blood testosterone

Description : Adrenaline: a. is synthesized by demethylation of noradrenaline b. increases coronary blood flow c. increases free fatty acids in the blood d. mobilizes glycogen stores from the liver

Last Answer : increases coronary blood flow

Description : Vasomotor reversal phenomenon after administration of an α adrenergic blocker is seen with: A. Adrenaline B. Noradrenaline C. Isoprenaline D. All of the above drugs

Last Answer : A. Adrenaline

Description : The following sympathomimetic amine has agonistic action on α1 + α2 + β1 + β3 adrenoceptors, but not on β2 receptors: A. Adrenaline B. Noradrenaline C. Isoprenaline D. Phenylephrine

Last Answer : B. Noradrenaline

Description : Vasomotor reversal phenomenon after administration of an α adrenergic blocker is seen with: A. Adrenaline B. Noradrenaline C. Isoprenaline D. All of the above drugs

Last Answer : A. Adrenaline

Description : The following sympathomimetic amine has agonistic action on α 1 + α 2 + β 1 + β 3 adrenoceptors, but not on β 2 receptors: A. Adrenaline B. Noradrenaline C. Isoprenaline D. Phenylephrine

Last Answer : B. Noradrenaline

Description : Which of the following vasoactive drugs used in treating shock results in reduced preload and afterload, reducing oxygen demand of the heart? a) Nitroprusside (Nipride) A disadvantage ... increases cardiac output. d) Methoxamine (Vasoxyl) Methoxamine increases blood pressure by vasoconstriction.

Last Answer : a) Nitroprusside (Nipride) A disadvantage of nitroprusside is that it causes hypotension.

Description : Which of the following is a noncatecholamine sympathomimetic: A. Adrenaline B. Ephedrine C. Dopamine D. Isoprenaline

Last Answer : B. Ephedrine

Description : Which of the following is a noncatecholamine sympathomimetic: A. Adrenaline B. Ephedrine C. Dopamine D. Isoprenaline

Last Answer : B. Ephedrine

Description : 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

Last Answer : Answer : B

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

Last Answer : Answer : C

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 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 : 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 : Which of the following statement(s) is/are true concerning cell membrane receptors? a. The largest family of cell surface receptors are the G-protein-linked receptors b. Activities of the ... through the use adenylate cyclase d. Tyrosine kinase receptors are considered G-protein-linked receptors

Last Answer : Answer: a, c All water-soluble regulatory molecules bind to the cell surface receptor proteins. Binding of the appropriate ligand evokes an intracellular signal which usually regulates ... are adenylate cyclase, which converts ATP to cAMP, and the polyphosphoinositide-specific phospholipase C

Description : Newly synthesized tRNA undergoes posttranscriptional modifications which include all the following except (A) Reduction in size (B) Methylation of some bases (C) Formation of pseudouridine (D) Addition of C-C-A terminus at 5’ end

Last Answer : Answer : D