Description : Aspirin inhibits the activity of the enzyme: (A) Lipoxygenase (B) Cyclooxygenase (C) Phospholipae A1 (D) Phospholipase A2
Last Answer : Answer : B
Description : Platelet activating factor is: a. Generated by the action of phospholipase A2 on membrane phospholipids b. Antiinflammatory in most of its actions c. Synthesized by endothelial and other cells d. Exerts a variety of biologic effects which are platelet-independent
Last Answer : Answer: a, c, d Like the eicosanoids, platelet-activating factor (PAF) is not stored in cells but is rapidly produced during inflammation. PAF exerts a variety of biologic effects ... and LTB4. There is considerable overlap and redundancy in the effects produced by PAF and eicosanoids
Description : Zellweger’s syndrome is due to inherited absence of (A) Peroxisomes (B) Phospholipase A1 (C) Acyl-Co-A dehydrogenase (D) Thiolase
Last Answer : Answer : A
Description : Lysolecithin is formed from lecithin by the action of (A) Phospholipase A1 (B) Phospholipase A2 (C) Phospholipase C (D) Phospholipase D
Description : Anti-inflammatory corticosteroids inhibit (A) Phospholipase A1 (B) Phospholipase A2 (C) Cyclo-oxygenase (D) Lipo-oxygenase
Description : Phenylbutazone and indomethacin inhibit (A) Phospholipase A1 (B) Phospholipase A2 (C) Cyclo-oxygenase (D) Lipo-oxygenase
Last Answer : Answer : C
Description : A ’suicide enzyme’ is (A) Cycloxygenase (B) Lipooxygenase (C) Phospholipase A1 (D) Phospholipase A2
Description : Vinca alkaloids exert antitumor activity by: A. Activating topoisomerase II to cause breaks in DNA strands B. Crosslinking DNA strands C. Inhibiting DNA mediated RNA synthesis D. Inhibiting polymerization of tubulin to form intracellular microtubules
Last Answer : D. Inhibiting polymerization of tubulin to form intracellular microtubules
Description : Dipalmitoyl lecithin acts as (A) Platelet activating factor (B) Second messenger for hormones (C) Lung surfactant (D) Anti-ketogenic compound
Description : All the following statements about steroid hormones are true except (A) They are hydrophobic (B) They require carriers to transport them in circulation (C) Their receptors are intracellular (D) They require cyclic AMP as second messenger
Last Answer : Answer : D
Description : Most hormone receptors are localized on the cell membrane and transduce hormone binding into altered levels of intracellular messengers. A limited number of intracellular receptors do exist. Which of ... protein serves as an inhibitor protein blocking the DNA-binding domain of the steroid receptor
Last Answer : Answer: a, d Although most hormone and other messenger receptors are extracellular, intracellular receptors have been identified. The hormone messengers involved for these receptors are primarily ... DNA-binding domain of the receptor. Activation involves the dissociation of the inhibitor protein
Description : Second messengers a. are substances that interact with first messengers inside cells b. are substances that bind to first messengers in the cell membrane c. are hormones secreted by cells ... the intracellular responses to many different hormonesand neurotransmitters e. are not formed in the brain
Last Answer : mediate the intracellular responses to many different hormonesand neurotransmitters
Description : Which of the following statement(s) is/are correct concerning the immunoinflammatory response to shock? a. The anaphylactoxins, C3a and C5a, are products of activation of only the classical pathway ... effects d. Platelet-activating factor can be released by both circulating and fixed tissue cells
Last Answer : Answer: d Inflammatory mediators have recently been recognized as playing a significant role in the clinical manifestations and progression of shock and the development ... increased pulmonary vascular resistance, bronchoconstriction, peripheral vasodilatation, and increased vascular permeability
Description : Which of the following statements regarding cytokines is incorrect? A. Cytokines act directly on target cells and may potentiate the actions of one another. B. Interleukin 1 (IL-1) ... organ dysfunction syndrome because of its multiple actions and the secondary cascades that it stimulates.
Last Answer : Answer: C DISCUSSION: Cytokines are soluble peptide molecules that are synthesized and secreted by a number of cell types in response to injury, inflammation, and infection. Cytokines, which ... is thought to play a central role in the stress response, particularly in response to endotoxemia
Description : Phospholipase C is activated by (A) Gs proteins (B) Gi proteins (C) Gq proteins (D) G12 proteins
Description : Activated phospholipase C acts on (A) Phosphatidyl inositol-4, 5-biphosphate (B) Inositol-1, 4, 5-triphosphate (C) Protein kinase C (D) Pl-3 kinase
Description : Binding of insulin to its receptor activates (A) Adenylate cyclase (B) Guanylate cyclase (C) Phospholipase C (D) Tyrosine kinase
Description : Phospholipase C attacks the ester bond liberating 1, 2-diacylglycerol and a phosphoryl base at position (A) 1 (B) 2 (C) Both (A) and (B) (D) 3
Description : Non steroidal anti inflammatory drugs, such as aspirin act by inhibiting the activity of the enzyme: (A) Lipoxygenase (B) Cyclooxygenase (C) Phospholipase A2 (D) Lipoprotein lipase
Description : Phospholipase A2 is an enzyme which removes a fatty acid residue from lecithin to form (A) Lecithin fragments (B) Phosphotidic acid (C) Glyceryl phosphate (D) Lysolecithin
Description : Apolipoprotein C-II is an activator of (A) Lecithin cholesterola acyl transferase (B) Phospholipase C (C) Extrahepatic lipoprotein lipase (D) Hepatic lipoprotein lipase
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
Description : If a coenzyme is required in an enzyme reaction, the former usually has the function of (A) Acting as an acceptor for one of the cleavage products of the substrate (B) Enhancing the specificity ... C) Increasing the number of receptor sites of the apo enzyme (D) Activating the substrate ENZYMES 167
Description : The hormone activating the glycogen synthase activity is (A) Insulin (B) Glucagon (C) Epinephrine (D) ACTH
Description : Prostaglandin synfhesis is increased by activating phospholipases by (A) Mepacrine (B) Angiotensin II (C) Glucocorticoids (D) Indomenthacin
Description : The molecule of vitamin A1 contains (A) Benzene ring (B) β-Ionone ring (C) β-Carotene ring (D) None of these
Description : Glutathione is a constituent of (A) Leukotriene A4 (B) Thromboxane A1 (C) Leukotriene C4 (D) None of these
Description : Colloid osmotic pressure of intracellular fluid is (A) Equal to that of plasma (B) More than that of plasma (C) More than that of plasma (D) Nearly zero WATER AND ELECTROLYTE BALANCE 285
Description : Of the total body water, intracellular compartment contains about (A) 50% (B) 60% (C) 70% (D) 80%
Description : A high serum potassium, accompanied by a high intracellular potassium occurs in (A) Adrenal insufficiency (B) Any illness (C) Gastrointestinal losses (D) Cushing’s syndrome
Description : The principal cation in intracellular fluid is (A) Sodium (B) Potassium (C) Calcium (D) Magnesium
Description : Important finding of secondary dehydration is (A) Intracellular oedema (B) Cellular dehydration (C) Thirst (D) Muscle cramps
Description : In primary dehydration (A) Intracellular fluid volume is reduced (B) Intracellular fluid volume remains normal (C) Extracellular fluid volume is much reduced (D) Extracellular fluid volume is much increased
Description : In intracellular compartment the fluid present in ml/kg body weight is about (A) 100 (B) 200 (C) 200 (D) 330
Description : The mean intracellular concentration of ATP in mammalian cell is about (A) 1 mM (B) 2 mM (C) 0.1 mM (D) 0.2 mM
Description : Hormonal stimulation of the formation of the second messenger inositol 1,4,5 triphosphate (IP3) quickly leads to the release of which other intracellular messenger? (A) cAMP (B) Prostaglandin (C) Calcinon (D) Leukotriene
Description : Insulin increases the permeability of glucose across the plasma membrane of muscle cells by (A) Acting on adenylate cycle (B) By loosening the integrity of the membrane (C) Through Ca2 ... membrane cruting the hexose carries of intracellular organelles and making them fuse with the plasma membrane
Description : Binding of catecholamines to α2− adrenergic receptors (A) Increases the intracellular concentration of cAMP (B) Increases the intracellular concentration of cGMP (C) Decreases the intracellular concentration of cAMP (D) Decreases the intracellular concentration of cGMP
Description : Hormone that binds to intracellular receptor is (A) Adrenocorticotropic hormone (B) Thyroxine (C) Follicle stimulating hormone (D) Glucagon
Description : What is the principal cation of intracellular fluid? (A) K+ (B) Na+ (C) Ca2+ (D) Mg2+
Description : Concentration of the following is higher in intracellular fluid than in extracellular fluid: (A) Sodium (B) Potassium (C) Chloride (D) Bicarbonate
Description : Rate of tissue respiration is raised when the intracellular concentration of (A) ADP increases (B) ATP increases (C) ADP decreases (D) None of these
Description : A nonspecific intracellular antioxidant is (A) Chromium (B) Magnesium (C) Selenium (D) Nickel
Description : During deficiency of thiamine the concentration of the following compound rises in blood and intracellular fluid: (A) Glycogen (B) Sugar (C) Amino acids (D) Pyruvic acid
Description : All the following statements describing lipids are true except (A) They usually associate by covalent interactions (B) They are structurally components of membranes (C) They are an intracellular energy source (D) They are poorly soluble in H2O
Description : Zymogen is (A) An intracellular enzyme (B) Serum enzyme (C) A complete extracellular enzyme (D) An inactivated enzyme
Description : The following points about microfilaments are true except (A) They form cytoskeleton with microtubules (B) They provide support and shape (C) They form intracellular conducting channels (D) They are involved in muscle cell contraction
Last Answer : C
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
Last Answer : Ans: D
Description : The mechanism of action of cyclosporine involves (a) Activation of calcineurin (b) Binding to cyclophilin to cause inhibition of a cytoplasmic phosphatase (c) Blockade of interleukin – 2- receptors (d) Inhibition of phospholipase A2 (e) Suppression of bone marrow progenitors
Last Answer : Ans: B
Description : Corticosteroids exert anti-inflammatory action by inhibiting the following enzyme (a) Cycloxygenase (b) Lipozygenase (c) Phospholipase - A (d) Phosphodiesterase
Last Answer : Ans: C