Description : Synthesis of phosphatidylinositol by transfer of inositol to CDP diacylglycerol is catalysed by the enzyme: (A) CTP phosphatidate cytidyl transferase (B) Phosphatidate phosphohydrolase (C) CDP-diacylglycerol inositol transferase (D) Choline kinase
Last Answer : Answer : C
Description : The enzyme regulating extramitochondrial fatty acid synthesis is (A) Thioesterase (B) Acetyl CoA carboxylase (C) Acyl transferase (D) Multi-enzyme complex
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 : Phenylephrine (a) Mimics the transmitter at post-synaptic receptors (b) Displaces transmitter from axonal terminal (c) Inhibits synthesis of transmitter (d) None of the above
Last Answer : Ans: A
Description : Guanethidine inhibits (a) Synthesis of transmitter (b) Metabolism of transmitter (c) Release of transmitter (d) Displacement of transmitter from axonal terminal
Last Answer : Ans: C
Description : The most efficacious inhibitor of catecholamine synthesis in the body is (a) a - methyl – p - tyrosine (b) a - methyldopa (c) a - methyl - norepinephrine (d) Pyrogallol
Description : Typical results of beta-receptor activation include which one of the following? (a) Hypoglycemia (b) Lipolysis (c) Glycogen synthesis (d) Decreased skeletal muscle tremor (e) Decreased rennin secretion
Last Answer : Ans: B
Description : The biochemical mechanism of action of digitalis is associated with (a) A decrease in calcium uptake by the sarcoplasmic reticulum (b) An increase in ATP synthesis (c) A modification of the actin molecule (d) An increase in systolic intracellular calcium levels (e) A block of sodium/calcium exchange
Last Answer : Ans: D
Description : Insulin regulates fatty acid synthesis by (A) Dephosphorylating of acetyl CoA carboxylase (B) Activating phosphorylase (C) Inhibiting malonyl CoA formation (D) Controlling carnitine-Acyl CoA transferase activity
Last Answer : Answer : A
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 : The most important mechanism by which gram negative bacilli acquire chloramphenicol resistance is (a) Decreased permeability into the bacterial cell (b) Acquisition of a plasmid encoded ... bacterial ribosome for chloramphenicol (d) Switching over from ribosomal to mitochondrial protein synthesis
Description : Defective enzyme in Hurler’s syndrome is (A) α-L-diuronidase (B) Iduronate sulphatase (C) Arylsulphatase B (D) C-acetyl transferase
Description : Defective enzyme in Hunter’s syndrome is (A) α-L-iduronidase (B) Iduronate sulphatase (C) Arylsulphatase B (D) C-acetyl transferase
Description : LCAT is (A) Lactose choline alamine transferse (B) Lecithin cholesterol acyl transferase (C) Lecithin carnitine acyl transferase (D) Lanoleate carbamoyl acyl transferase
Description : Methotrexate blocks the synthesis of thymidine monophosphate by inhibiting the activity of the enzyme: (A) Dihydrofolate reductase (B) Orotate phosphoribosyl transferase (C) Ribonucleotide reductase (D) Dihydroorotase
Description : Synthesis of polyunsaturated fatty acids involves the enzyme systems: (A) Acyl transferase and hydratase (B) Desaturase and elongase (C) Ketoacyl-CoA reductase and hydratase (D) Dihydroxyacetone phosphate
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 ß-adrenergic blocker which possesses both ß1 selectivity as well as intrinsic sympathomimetic activity is (a) Alprenolol (b) Atenolol (c) Acebutolol (d) Metoprolol
Description : Ephedrine is similar to adrenaline in the following feature (a) Potency (b) Inability to penetrate blood-brain barrier (c) Duration of action (d) Producing both a and ß adrenergic effects
Description : Yohimbine is an antagonist of ______ receptors. (a) a1 (b) a2 (c) both (a) and (b) (d) None of the above
Description : The synaptic pre-ganglionic neurons have their cell bodies in the lateral horn of the grey matter of the (a) Thoracic segment only (b) Lumbar segment only (c) Both (a) and (b) (d) None of the above
Description : Acetyl Choline causes `:-`
Last Answer : Acetyl Choline causes `:-` A. Bradycardia B. Tachycardia C. Both D. None
Description : ADP ribosylation is the mode of action of (A) Cholera toxin (B) Acetyl choline (C) Muscerinic receptors (D) Cyclic AMP
Description : Prolactin release inhibiting hormone is believed to be (A) Serotonin (B) Norepinephrine (C) Dopanine (D) Acetyl choline
Description : Choline is not required for the formation of (A) Lecithins (B) Acetyl choline (C) Sphingomyelin (D) Cholic acid
Last Answer : Answer : D
Description : Sphingosine is synthesized from (A) Palmitoyl CoA and Choline (B) Palmitoyl CoA and ethanolamine (C) Palmitoyl CoA and serine (D) Acetyl CoA and choline
Description : The following are true about acetylcholine: a. it has a strong affinity for nicotinic receptors b. is derived from acetyl CoA and choline c. is synthesized by a reaction involving choline acetyltransferase 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 : In gluconeogensis, an allosteric activator required in the synthesis of oxaloacetate from bicarbonate and pyruvate, which is catalysed by the enzyme pyruvate carboxylase is (A) Acetyl CoA (B) Succinate (C) Isocitrate (D) Citrate
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 : In urea synthesis, the amino acid functioning solely as an enzyme activator: (A) N-acetyl glutamate(B) Ornithine (C) Citrulline (D) Arginine
Description : Acetyl CoA from mitochondria is transferred to cytoplasm for the de novo synthesis of fatty acid, by which enzyme?
Last Answer : ATP citrate lyase.
Description : Pralidoxime can reactivate cholinesterase enzyme that has been inactivated by: A. Carbamate anticholinesterases B. Organophosphate anticholinesterases C. Both carbamate and organophosphate anticholinesterases D. Reversible anticholinesterases
Last Answer : B. Organophosphate anticholinesterases
Description : Propranolol does not block the following action of adrenaline (a) Bronchodilation (b) Lipolysis (c) Muscle tremor (d) Mydriasis
Description : Propanolol can be used to allay anxiety associated with (a) Chronic neurotic disorer (b) Schizopherenia (c) Short-term stressful situation (d) Endogenous depression
Description : Which of the following is true of sildenafil (a) It enhances sexul enjoyment in normal men (b) It delays ejaculation (c) It is indicated only for treatment of erectile dysfunction in men (d) It blocks cavernosal a2 adrenoceptors
Description : Prazosin is an effective antihypertensive while nonselective a adrenergic blockers are not because (a) It is the only orally active a blocker (b) It improves plasma lipid profile (c) It does not concurrently enhance noradrenaline release (d) It improves urine flow in males with prostatic hypertrophy
Description : The drug which produces vasoconstriction despite being an a adrenergic blocker is (a) Phenoxybenzamine (b) Ergotamine (c) Dihydroergotoxine (d) Tolazoline
Description : Vasoconstrictors should not be used in (a) Neurogenic shock (b) Haemorrhagic shock (c) Secondary shock (d) Hypotension due to spinal anaesthesia
Description : While undergoing a surgical procedure a patient develops hypotension. Which of the following drugs can be injected intramuscularly to raise his BP (a) Noradrenaline (b) Isoprenaline (c) Mephentermine (d) Isoxsuprine
Description : Continuous exposure of ctecholaminesensitive cells and tissues to adrenergic agonists causes a progressive diminition in their capacity to respond, this phenomenon is called as (a) Refractoriness (b) Desensitization (c) Tachyphylaxis (d) All of the above
Description : Dobutamine differs from dopamine in that (a) It does not activate peripheral dopaminergic receptors (b) It does not activate adrenergic ß receptors (c) It causes pronounced tachycardia (d) It has good blood-brain barrier penetrability
Description : Noradrenaline is administered by (a) Subcutaneous injection (b) Intramuscular injection (c) Slow intravenous infusion (d) All of the above routes
Description : Adrenaline raises blood glucose level by the following actions except (a) Inducing hepatic glycogenolysis (b) Inhibiting insulin secretion from pancreatic ß cells (c) Augmenting glucagons secretion from pancreatic a cells (d) Inhibiting peripheral glucose utilization
Description : a2–adrenergic receptors are associated with following except (a) Increase in phospholipase C activity (b) Increase in potassium channel conductance (c) Decrease in calcium channel conductance (d) Increase in adenylyl cyclase activity
Description : Low doses of adrenaline dilate the following vascular bed (a) Cutaneous (b) Mucosal (c) Renal (d) Skeletal muscle
Description : A sympathomimetic amine that acts almost exclusively by releasing noradrenaline from the nerve endings is (a) Ephedrine (b) Dopamine (c) Isoprenaline (d) Tyramine
Description : Choose the correct statement from the following about a1 – adrenergic receptor agonists (a) Norepinephrine > isoproterenol > epinephrine (b) Norepinephrine < epinephrine > isoproterenol (c) Epinephrine = norepinephrine >> isoproterenol (d) Epinephrine > isoproterenol > norepinephrine