Description : Give examples for suicide inhibition.
Last Answer : Ornithine decarboxylase (ODC) is inhibited by difluro methyl ornithine (DFMO). Another example is Allopurinol which is oxidised by xanthine oxidase to alloxanthine that is a strong inhibitor of xanthine oxidase.
Description : What is the other term for suicide inhibition?
Last Answer : Mechanism based inactivation.
Description : One of the important functions of prostacyclins is (A) Inhibition of platelet aggregation (B) Contraction of uterus (C) Decrease of gastric secretion (D) Relieving osthma
Last Answer : Answer : A
Description : The blood sugar raising action of the hormone of suprarenal cortex is due to (A) Glyconeogenesis (B) Glycogenolysis (C) Glucagon like activity (D) due to inhibition of glomerular filtration of glucose
Description : Regulation of ACTH secretion occurs through (A) Corticotropin releasing hormone (CRH) and corticotropin release inhibiting hormone (CRIH) of hypothalamus (B) Feedback inhibition by cortisol (C) CRH and feedback inhibition by cortisol (D) CRIH and feedback inhibition by cortisol
Last Answer : Answer : C
Description : Secretion of prolactin is regulated by (A) Feedback inhibition (B) Prolactin releasing hormone (C) Prolactin release inhibiting hormone (D) All of these
Description : Secretion of growth hormone is inhibited by (A) Somatomedin C (B) Somatostatin (C) Feedback inhibition(D) All of these
Last Answer : Answer : B
Description : Down regulation is (A) Increased destruction of a hormone (B) Feed back inhibition of hormone secretion (C) Decreased concentration of a hormone in blood (D) Decrease in number of receptors for a hormone
Last Answer : Answer : D
Description : Allosteric inhibition (A) Makes active site unifit for substrate (B) Controls excess formation and end product (C) Both (A) and (B) (D) None of these
Description : An example of feedback inhibition is (A) Allosteric inhibition of hexokinase by glucose6-phosphate (B) Cyanide action on cytochrome (C) Sulpha drug on folic acid synthesizer bacteria (D) Reaction between succinic dehydrogenase and succinic acid
Description : Feedback inhibition of enzyme is influenced by (A) Enzyme (B) External factors (C) End product (D) Substrate
Description : Enzyme inhibition caused by a substance resembling substrate molecule is (A) Competitive inhibition (B) Non-competitive inhibition (C) Feedback inhibition (D) Allosteric inhibition
Description : Feedback inhibition of enzyme action is affected by (A) Enzyme (B) Substrate (C) End products (D) None of these
Description : Which one of the following regulatory actions involves a reversible covalent modification of the enzyme? (A) Phosphorylation of ser-OH on the enzyme (B) Allosteric modulation (C) Competitive inhibition (D) Non-competitive inhibition
Description : In competitive inhibition which of the following kinetic effect is true ? (A) Decreases both Km and Vmax (B) Increases both Km and Vmax (C) Decreases Km without affecting Vmax (D) Increases Km without affecting Vmax
Description : In competitive inhibition of enzyme action (A) The apparent Km is decreased (B) The apparent Km is increased (C) Vmax is decreased (D) Apparent concentration of enzyme molecules decreased
Description : Which of the following regulatory reactions involves a reversible covalent modification of an enzyme? (A) Phosphorylation of serine OH on the enzyme (B) Allosteric modulation (C) Competitive inhibition (D) Non-competitive inhibition
Description : The inhibition of succinate dehydrogenase by malonate by (A) Competitive inhibition (B) Non-competitive inhibition (C) Uncompetitive inhibition (D) Feedback inhibition
Description : Allosteric enzymes regulate the formation of products by (A) Feedback inhibition (B) Non-competitive inhibition (C) Competitive inhibition (D) Repression-derepression
Description : Competitive inhibition can be relieved by raising the (A) Enzyme concentration (B) Substrate concentration (C) Inhibitor concentration (D) None of these
Description : In competitive inhibition, the inhibitor (A) Competes with the enzyme (B) Irreversibly binds with the enzyme (C) Binds with the substrate (D) Competes with the substrate
Description : Allosteric inhibition is also known as (A) Competitive inhibition (B) Non-competitive inhibition (C) Feedback inhibition (D) None of these
Description : An example of enzyme inhibition: (A) Reversible inhibition (B) Irreversible inhibition (C) Allosteric inhibition (D) All of these ENZYMES 151
Description : In non competitive enzyme activity inhibition, inhibitor (A) Increases Km (B) Decreases Km (C) Does not effect Km (D) Increases Km
Description : In competitive enzyme activity inhibition (A) Apparent Km is decreased (B) Apparent Km is increased (C) Vmax is increased (D) Vmax is decreased
Description : In competitive enzyme activity inhibition (A) The structure of inhibitor generally resembles that of the substrate (B) Inhibitor decreases apparent Km (C) Km remains unaffective (E) Inhibitor decreases Vmax without affecting Km
Description : In reversible non-competitive enzyme activity inhibition (A) Inhibitor bears structural resemblance to substrate (B) Inhibitor lowers the maximum velocity attainable with a given amount of enzyme (C) Km is increased (D) Km is decreased
Description : In reversible non-competitive enzyme activity inhibition (A) Vmax is increased (B) Km is increased (C) Km is decreased (D) Concentration of active enzyme is reduced
Description : If curve X in the graph (below) represents no inhibition for the reaction of the enzyme with its substrates, the curve representing the competitive inhibition, of the same reaction is (A) A (B) B (C) C (D) D
Description : A sigmoidal plot of substrate concentration ([S]) verses reaction velocity (V) may indicate (A) Michaelis-Menten kinetics (B) Co-operative binding (C) Competitive inhibition (D) Non-competitive inhibition
Description : The phenomenon of inhibition of glycolysis by O2 is termed as (A) Red drop (B) Pasteur effect (C) Michaelis effect (D) Fischer’s effect
Description : Secretin causes all of the following except (A) Secretion of pancreatic juice (B) Secretion of bile (C) Inhibition of gastric secretion (D) Stimulation of intestinal motility
Description : The primary biochemical lesion in homozygote with familial hypercholesterolemia (type IIa) is (A) Loss of feed back inhibition of HMG reductase (B) Loss of apolipoprotein B (C) Increased production of LDL from VLDL (D) Functional deficiency of plasma membrane receptors for LDL
Description : Pasteur effect is (A) Inhibition of glycolysis (B) Oxygen is involved (C) Inhibition of enzyme phosphofructokinase (D) All of these
Last Answer : D
Description : The blood sugar raising action of the hormones of suprarenal cortex is due to (A) Gluconeogenesis (B) Glycogenolysis (C) Glucagon-like activity (D) Due to inhibition of glomerular filtration
Last Answer : A
Description : What is the importance of the above inhibition?
Last Answer : Fluoride is used to prevent glycolysis, as preservative for blood before glucose estimation.
Description : Give examples for allosteric inhibition.
Last Answer : ALA synthase, aspartyl trans-carbamoylase, HMG CoA reductase
Description : What are the salient features of allosteric inhibition?
Last Answer : (1) The inhibitor is not a substrate analogue. (2) It is partially reversible when excess substrate is added. (3) Km is usually increased. (4) Vmax is reduced. (5) Most allosteric enzymes possess quaternary structure. They are made up of subunits.
Description : What is allosteric inhibition?
Last Answer : Allosteric enzyme has one catalytic site where the substrate binds and another separate allosteric site where the modifier binds.
Description : Give examples of non-competitive inhibition.
Last Answer : Di-isopropyl fluoro phosphate inhibits trypsin, fluoride inhibits and enolase.
Description : What are the salient features of non-competitive inhibition?
Last Answer : Non-competitive inhibitor has no structural similarity with the substrate. 2. It is generally not reversible 3. Km is not changed. 4. Vmax is reduced.
Description : Give examples of clinical application of competitive inhibition.
Last Answer : Sulfonamide inhibits PABA incorporation in bacteria, and so acts as an antibacterial agent. Methotrexate inhibits folate reductase system, dicoumarol inhibits vitamin K.
Description : Give examples of competitive inhibition.
Last Answer : Malonate inhibits succinate dehydrogenase.
Description : What are salient features of competitive inhibition?
Last Answer : Competitive inhibitor is a structural analogue. 2. It is reversible. 3. Km is increased. 4. Vmax is not changed.
Description : A ’suicide enzyme’ is (A) Cycloxygenase (B) Lipooxygenase (C) Phospholipase A1 (D) Phospholipase A2
Description : The cellular organelles called “suicide bags” are (A) Lysosomes (B) Ribosomes (C) Nucleolus (D) Golgi’s bodies
Description : What is Competitive Inhibition -Biology
Last Answer : answer:
Description : What is non-competitive Inhibition? -Biology
Description : Difference between competitive and allosteric inhibition -Biology
Description : Antibiotic resistance genes zone of inhibition -Biology