Description : True statements regarding eicosanoids include which of the following? A. Prostaglandins and thromboxanes are synthesized via the cyclo-oxygenase pathway. B. The vasoconstricting, platelet-aggregating, ... prostaglandins have a short circulation half-life and exert most of their effects locally.
Last Answer : Answer: ABD DISCUSSION: The eicosanoids are a group of compounds arising from the metabolism of arachidonic acid. The prostaglandins and thromboxanes are synthesized via the cyclo-oxygenase ... effects and may be involved in the physiologic responses associated with anaphylactic and septic shock
Description : Lipo-oxygenase is required for the synthesis of (A) Prostaglandins (B) Leukotrienes (C) Thromboxanes (D) All of these
Last Answer : Answer : B
Description : Prostaglandins are inactivated by (A) 15-Hydroxyprostaglandin dehydrogenase (B) Cyclo-oxygenase (C) Lipo-oxygenase (D) None of these
Last Answer : Answer : A
Description : Aspirin blocks the synthesis of (A) Prostaglandins only (B) Prostacyclins only (C) Thromboxanes only (D) All of these
Last Answer : Answer : D
Description : Anti-inflammatory corticosteroids inhibit the synthesis of (A) Leukotrienes (B) Prostaglandins (C) Thromboxanes (D) All of these
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 : Which of the following is used for inducing labour? (A) Prostaglandins (B) Prostacyclins (C) Vasopressin (D) Thromboxanes
Description : Slow reacting Substance of Anaphylaxis is a mixture of (A) Prostaglandins (B) Prostacyclins (C) Thromboxanes (D) Leukotrienes
Description : By which of the following mechanism reduces Aspirin pain: A. It is anti inflammatory by the release of histamine B. It blocks the cyclo-oxygenase pathway.
Last Answer : B. It blocks the cyclo-oxygenase pathway.
Description : Eicosanoids mediate inflammation in a variety of ways. Of the following statements, which are true with regard to this? a. Eicosanoids are stored in cytoplasmic granules ... include vasodilatation, vasoconstriction, increased vascular permeability and both chemotaxis and chemoattractant inhibition
Last Answer : Answer: b, d The eicosanoids are derived from arachidonic acid (eicosatetraenoic acid) and consist of prostaglandins, thromboxanes, leukotrienes and lipoxins. The eicosanoids are not ... nervous system d. Mononuclear phagocytes release a variety of proinflammatory cytokines and growth factors
Description : A cup of strong coffee would be expected to (A) Interfere with synthesis of prostaglandins (B) Decrease the effects of Glucagon (C) Enhance the effects of epinephrine (D) Provide the vitamin nicotinic acid
Description : A cup of strong coffee would be expected to (A) Interfere with the synthesis of prostaglandins (B) Decrease the effect of glucagon (C) Enhance the effect of epinephrine (D) Provide the vitamin nicotinic acid
Description : From arachidonate, synthesis of prostaglandins is catalysed by (A) Cyclooxygenase (B) Lipoxygenase (C) Thromboxane synthase (D) Isomerase
Description : Synthesis of prostaglandins is inhibited by (A) Glucocorticoids (B) Aspirin (C) Indomethacin (D) All of these
Description : For synthesis of prostaglandins, the essential fatty acids give rise to a fatty acid containing (A) 12 carbon atoms (B) 16 carbon atoms (C) 20 carbon atoms (D) 24 carbon atoms
Description : Which of the following anzymes is involved in the primary carboxylation in C4 plants? (a) RUBP Carboxylase (b) PEP(c) Oxygenase (d) Carboxylase
Last Answer : (b) PEP
Description : Thromboxanes cause (A) Vasodilation (B) Bronchoconstriction (C) Platelet aggregation (D) All of these
Description : Microsomal hydroxylase system contains a (A) Di-oxygenase (B) Mono-oxygenase (C) Both (A) and (B) (D) None of thse
Description : Name the enzyme that acts both as carboxylase at one time and oxygenase at another time. (A) PEP carboxylase (B) RuBP carboxylase (C) Carbonic anyhdrase (D) None of these
Description : Cyclooxygenase-1 and –2 are responsible for (a) The synthesis of prostaglandins from arachidonate (b) The synthesis of leukotrienes from arachidonate (c) The conversion of ATP to cAMP (d) The metabolic degradation of cAMP (e) The conversion of GTP to cGMP
Last Answer : Ans: A
Description : .Which of these is not an important component of initiation of parturition in humans? (a) Release of oxytocin (b) Release of prolactin (c) Increase in estrogen and progesterone ratio (d) Synthesis of prostaglandins
Last Answer : b) Release of prolactin
Description : The enzyme catalyzing conversion of androstenedione to testosterone is a (A) Oxygenase (B) Dehydrogenase (C) Isomerase (D) Decarboxylase
Description : Isocitrate dehydrogenases is (A) Aerobic dehydrogenase (B) Anaerobic dehydrogenase (C) Hydroperoxidase (D) Oxygenase
Description : In which of the following types of enzymes, water may be added to a C—C double bond without breaking the bond? (A) Hydrolase (B) Hydratase (C) Hydroxylase (D) Oxygenase
Description : Tryptophan pyrolase is currently known as (A) Tryptophan deaminase (B) Tryptophan dioxygenase (C) Tryptophan mono oxygenase (D) Tryptophan decarboxylase
Description : An enzyme which uses hydrogen acceptor as substrate is (A) Xanthine oxidase (B) Aldehyde oxidase (C) Catalase (D) Tryptophan oxygenase
Description : β-Carotene, precursor of vitamin A, is oxidatively cleaved by (A) β-Carotene dioxygenase (B) Oxygenase (C) Hydroxylase (D) Transferase
Description : Inflammation is a complex tissue reaction that includes the release of cytokines, leukotrienes, prostaglandins, and peptides. Prostaglandins involved in inflammatory processes are produced from arachidonic acid by (a) ... 2 (c) Glutathione - S - transferase (d) Lipoxygenase (e) Phospholipase A2
Last Answer : Ans: B
Description : The following are true about chemicals involved in allergic reaction: a. thromboxane -leukocyte activation b. prostaglandin-2 - vasodilatation c. platelet-activating factor - leukocyte activation d. heparin - augments inactivation of prostaglandins
Last Answer : prostaglandin-2 - vasodilatation
Description : The ‘rho’ (ρ) factor is involved (A) To increase the rate of RNA synthesis (B) In binding catabolite repressor to the promoter region (C) In proper termination of transcription (D) To allow proper initiation of transcriptide
Description : The enzyme amino acyl tRNA synthetase is involved in (A) Dissociation of discharged tRNA from 80S ribosome (B) Charging of tRNA with specific amino acids (C) Termination of protein synthesis (D) Nucleophilic attack on esterified carboxyl group of peptidyl tRNA
Description : Coenzymes derived from the vitamin shown below are required by enzymes involved in the synthesis of which of the following? (A) ATP (B) UTP (C) CTP (D) NADH
Description : All the enzymes involved in the synthesis of cholesterol are found in (A) Mitochondria (B) Golgi apparatus (C) Nucleus (D) Endoplasmic reticulum and cytosol
Description : Retinoic acid is involved in the synthesis of (A) Rhodopsin (B) Iodopsin (C) Porphyrinopsin (D) Glycoproteins
Description : All the following correctly describe the intermediate 3-OH-3-methyl glutaryl CoA except (A) It is generated enzymatically in the mitochondrial matrix (B) It is formed in the cytoplasm (C) It inhibits the first step in cholesterol synthesis (D) It is involved in the synthesis of ketone bodies
Description : All statements regarding 3-OH-3 methyl glutaryl CoA are true except (A) It is formed in the cytoplasm (B) Required in ketogenesis (C) Involved in synthesis of Fatty acid (D) An intermediate in cholesterol biosynthesis
Description : Acyl carrier protein is involved in the synthesis of (A) protein (B) glycogen (C) fatty acid outside the mitochondria (D) fatty acid in the mitochondria
Description : The amino acids involved in the synthesis of creatin are (A) Arginine, glycine, active methionine (B) Arginine, alanine, glycine (C) Glycine, lysine, methionine (D) Arginine, lysine, methionine
Description : The activity of kinins is modulated by (A) Prostaglandins (B) Ca++ (C) Increased cAMP level (D) Increased cGMP level
Description : Which one of the following hormones is derived most completely from tyrosine? (A) Glucagon (B) Thyroxine (C) Insulin (D) Prostaglandins
Description : The suffix number in the names of prostaglandins gives the number of (A) OH groups (B) Double bonds (C) Acid groups (D) Ketoacids
Description : Which of tne of the following scientists has not worked in the field of prostaglandins? (A) Voneuler (B) Sultan Karim (C) Andre robet (D) Kendal
Description : Prostaglandins are (A) C2 unsaturated acids (B) C27 saturated alcohols (C) C20 saturated acids (D) C27 saturated alcohols
Description : Which of the following property of prostaglandins has been utilized by chinicians in hospital for (A) Inducing fever (B) Causing inflammation (C) Effecting smooth muscle contraction (D) Disaggregation of spermatozoa
Description : Richest source of prostaglandins in a human male is (A) Blood (B) Urine (C) Semen (D) C.S.F.
Description : Cholesterol is the precursor for the biosynthesis of (A) fatty acid (B) prostaglandins (C) bile acids (D) sphingmyelin
Description : Acrolein Test is positive for (A) Glycerol (B) Prostaglandins (C) Carbohydrates (D) Proteins
Description : All the following are functions of prostaglandins except (A) Lowering of B.P (B) Introduction of labour (C) Anti inflammatory (D) Prevention of myocardial infraction
Description : Prostaglandins are synthesized in the body from (A) Myristic acid (B) Arachidonic acid (C) Stearic acid (D) Lignoceric acid