Description : Which of the following is a G protein coupled receptor: A. Muscarinic cholinergic receptor B. Nicotinic cholinergic receptor C. Glucocorticoid receptor D. Insulin receptor
Last Answer : A. Muscarinic cholinergic receptor
Description : Cholinergic muscarinic receptor stimulation produces the following effects except: A. Sweating B. Rise in blood pressure C. Bradycardia D. Urination
Last Answer : B. Rise in blood pressure
Description : The following receptor type has 7 helical membrane spanning amino acid segments with 3 extracellular and 3 intracellular loops: A. Tyrosine protein kinase receptor B. Gene expression regulating receptor C. Intrinsic ion channel containing receptor D. G protein coupled receptor
Last Answer : D. G protein coupled receptor
Description : Muscarinic cholinergic receptors: A. Are located only on parasympathetically innervated effector cells B. Mediate responses by opening an intrinsic Na+ ion channel C. Are present on vascular endothelium which has no cholinergic nerve supply D. Predominate in the autonomic ganglia
Last Answer : C. Are present on vascular endothelium which has no cholinergic nerve supply
Description : Agonist induced autophosphorylation, internalization and down regulation is a distinctive feature of: A. G-protein coupled receptors B. Intrinsic ion channel containing receptors C. Tyrosine protein kinase receptors D. Receptors regulating gene expression
Last Answer : C. Tyrosine protein kinase receptors
Description : The insulin receptor is a: A. Ion channel regulating receptor B. Tyrosine protein kinase receptor C. G-protein coupled receptor D. None of the above
Last Answer : B. Tyrosine protein kinase receptor
Description : The major postjunctional cholinergic receptor is of the muscarinic type at the following site: A. Postganglionic parasympathetic B. Adrenal medulla C. Autonomic ganglia D. Neuromuscular junction
Last Answer : A. Postganglionic parasympathetic
Description : A receptor which itself has enzymatic property is: A. Insulin receptor B. Progesterone receptor C. Thyroxine receptor D. Glucagon receptor
Last Answer : A. Insulin receptor
Description : 81. Which one of the following pairs of hormones are the examples of those that can easily pass through the cell membrane of the target cell and bind to a receptor inside it (mostly in the nucleus) (1) Cortisol, testosterone (2) Insulin, glucagon (3) Thyroxin, Insulin (4) Somatostatin, oxytocin
Last Answer : Cortisol, testosterone
Description : Phosphorylated IRS-1 activates GRB-2 which is (A) G-protein receptor binding protein-2 (B) Growth factor receptor binding protein-2 (C) Growth hormone receptor binding protein-2 (D) Glucocorticoid receptor binding protein-2 226 MCQs IN BIOCHEMISTRY
Last Answer : Answer : B
Description : The receptor transduction mechanism with the fastest time-course of response effectuation is: A. Adenylyl cyclase-cyclic AMP pathway B. Phospholipase C-IP3: DAG pathway C. Intrinsic ion channel operation D. Protein synthesis modulation
Last Answer : C. Intrinsic ion channel operation
Description : Agonists affect the receptor molecule in the following manner: A. Alter its amino acid sequence B. Denature the receptor protein C. Alter its folding or alignment of subunits D. Induce covalent bond formation
Last Answer : C. Alter its folding or alignment of subunits
Description : Pyridostigmine differs from neostigmine in that: A. It is more potent orally B. It is longer acting C. It produces less muscarinic side effects D. It does not have any direct action on NM receptors
Last Answer : B. It is longer acting
Description : The cardiac muscarinic receptors: A. Are of the M1 subtype B. Are of the M2 subtype C. Are selectively blocked by pirenzepine D. Function through the PIP2 → IP3/DAG pathway
Last Answer : B. Are of the M2 subtype
Description : All of the following subserve as intracellular second messengers in receptor mediated signal transduction except: A. Cyclic AMP B. Inositol trisphosphate C. Diacyl glycerols D. G proteins
Last Answer : D. G proteins
Description : Edrophonium is more suitable for differentiating myasthenic crisis from cholinergic crisis because of its: A. Shorter duration of action B. Longer duration of action C. Direct action on muscle end-plate D. Selective inhibition of true cholinesterase
Last Answer : A. Shorter duration of action
Description : The smooth muscle structure that is relaxed by cholinergic drugs is: A. Colon B. Gastric fundus C. Major bronchi D. Bladder trigone
Last Answer : D. Bladder trigone
Description : Neostigmine is preferred over physostigmine for treating myasthenia gravis because: A. It is better absorbed orally B. It has longer duration of action C. It has additional direct agonistic action on nicotinic receptors at the muscle end plate D. It penetrates blood-brain barrier
Last Answer : C. It has additional direct agonistic action on nicotinic receptors at the muscle end plate
Description : Receptors perform the following function/functions: A. Ligand recognition B. Signal transduction C. Both ligand recognition and signal transduction D. Disposal of agonists and antagonists
Last Answer : D. Disposal of agonists and antagonists
Description : The following 5-HT receptor is not a G protein coupled receptor: A. 5-HT1 B. 5-HT2 C. 5-HT3 D. 5-HT4
Last Answer : C. 5-HT3
Description : G-proteins: a. are activated by the binding of an extracellular ligand to a membrane receptor b. can be mutated in tumour cells c. mediate the action of glucocorticoid hormone d. they are inactivated by cholera toxins
Last Answer : are activated by the binding of an extracellular ligand to a membrane receptor
Description : Which one of the following drugs does NOT act through G-Protein coupled receptors? (A) Epinephrine (B) Insulin (C) Dopamine (D) TSH
Last Answer : (B) Insulin
Description : Muscarinic cholinergic receptors (a) Are located only on parasympathetically innervated effector cells (b) Mediate responses by opening an instrinsic Na+ ion channel (c) Are present on vascular endothelium which has no cholinergic nerve supply (d) Predominate in the autonomic ganglia
Last Answer : Ans: C
Description : Norepinephrine binds mainly to (A) α-Adrenergic receptors (B) β-Adrenergic receptrors (C) Muscarinic receptors (D) Nicotinic receptors
Last Answer : Answer : A
Description : Which of the following best describes the mechanism of action of scopolamine ? (a) Irreversible antagonist at nicotinic receptors (b) Irreversible antagonist at muscarinic receptors (c) ... receptors (d) Reversible antagonist at muscarinic receptors (e) Reversible antagonist at nicotinic receptors
Last Answer : Ans: D
Description : The following are true about acetylcholine receptors: a. receptors at all autonomic ganglia are nicotinic b. receptors at the skeletal neuromuscular junction are muscarinic c. ... atropine d. acetylcholine receptors in the neuromuscular junction can be selectively blocked by tubocurarine
Last Answer : acetylcholine receptors in the neuromuscular junction can be selectively blocked by tubocurarine
Description : The plasma half life of penicillin-G is longer in the new born because their: A. Plasma protein level is low B. Drug metabolizing enzymes are immature C. Glomerular filtration rate is low D. Tubular transport mechanisms are not well developed
Last Answer : D. Tubular transport mechanisms are not well developed
Description : The following is not a feature of competitive antagonists: A. Chemical resemblance with the agonist B. Parallel rightward shift of the agonist log doseresponse curve C. Suppression of maximal agonist response D. Apparent reduction in agonist affinity for the receptor
Last Answer : C. Suppression of maximal agonist response
Description : Receptor agonists possess: A. Affinity but no intrinsic activity B. Intrinsic activity but no affinity C. Affinity and intrinsic activity with a + sign D. Affinity and intrinsic activity with a – sign
Last Answer : C. Affinity and intrinsic activity with a + sign
Description : Study of drug-receptor interaction has now shown that: A. Maximal response occurs only when all receptors are occupied by the drug B. Drugs exert an all or none' action on a ... lock and key' structural features D. Properties of affinity' and intrinsic activity' are independently variable
Last Answer : D. Properties of ‘affinity’ and ‘intrinsic activity’ are independently variable
Description : What is true in relation to drug receptors: A. All drugs act through specific receptors B. All drug receptors are located on the surface of the target cells C. Agonists induce a conformational change in the receptor D. Partial agonists have low affinity for the receptor
Last Answer : C. Agonists induce a conformational change in the receptoR
Description : Agonistic action on which of the following adrenergic receptors located on ciliary epithelial cells reduces aqueous secretion: A. β1 receptor B. β2 receptor C. α1 receptor D. α2 receptor
Last Answer : D. α2 receptor
Description : Select the receptor that is located intracellularly: A. Opioid μ receptor B. Steroid receptor C. Prostaglandin receptor D. Angiotensin receptor
Last Answer : B. Steroid receptor
Description : The following receptor has an intrinsic ion channel: A. Histamine H1 receptor B. Histamine H2 receptor C. Adrenergic alfa receptor D. GABA-benzodiazepine receptor
Last Answer : D. GABA-benzodiazepine receptor
Last Answer : C. Agonists induce a conformational change in the receptor
Description : The β3 adrenoceptor differs from the other subtypes of β receptor in that it: A. Is not blocked by the conventional doses of propranolol B. Is located primarily in the heart C. Regulates blood sugar level D. Is not coupled to G proteins
Last Answer : A. Is not blocked by the conventional doses of propranolol
Description : The β 3 adrenoceptor differs from the other subtypes of β receptor in that it: A. Is not blocked by the conventional doses of propranolol B. Is located primarily in the heart C. Regulates blood sugar level D. Is not coupled to G proteins
Description : A drug which is generally administered in standard doses without the need for dose individualization is: A. Insulin B. Mebendazole C. Prednisolone D. Digoxin
Last Answer : B. Mebendazole
Description : The glucocorticoid receptor is located: A. On the outer surface of the cell membrane B. On the inner surface of the cell membrane C. In the cytoplasm D. Inside the nucleus
Last Answer : C. In the cytoplasm
Description : Cisapride enhances gastrointestinal motility by: A. Activating serotonin 5-HT4 receptor B. Activating muscarinic M3 receptor C. Blocking dopamine D2 receptor D. All of the above
Last Answer : A. Activating serotonin 5-HT4 receptor
Description : Choose the correct statement(s) about dofetilide: A. It is a pure class III antiarrhythmic B. It has no adrenergic/cholinergic receptor blocking property C. It selectively depresses the rapid component of delayed rectifier K+ current in myocardial fibres D. All of the above
Last Answer : D. All of the above
Description : Select the hypolipidemic drug that enhances lipoprotein synthesis, fatty acid oxidation and LDLreceptor expression in liver through paroxisome proliferator-activated receptor α: A. Lovastatin B. Atorvastatin C. Bezafibrate D. Nicotinic acid
Last Answer : C. Bezafibrate
Description : The quarternary analogues of belladonna alkaloids are preferred over the natural alkaloids for antisecretory/ antispasmodic indications because: A. They have additional nicotinic receptor blocking activity B. They are ... of CNS and ocular effects D. Dose to dose they are more potent than atropine
Last Answer : C. They are devoid of CNS and ocular effects