Description : Give examples of non-competitive inhibition.
Last Answer : Di-isopropyl fluoro phosphate inhibits trypsin, fluoride inhibits and enolase.
Description : Give examples of competitive inhibition.
Last Answer : Malonate inhibits succinate dehydrogenase.
Description : Enzyme inhibition caused by a substance resembling substrate molecule is (A) Competitive inhibition (B) Non-competitive inhibition (C) Feedback inhibition (D) Allosteric inhibition
Last Answer : Answer : A
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
Last Answer : Answer : D
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
Last Answer : Answer : B
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
Last Answer : Answer : C
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 : 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 : 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 : Give examples for allosteric inhibition.
Last Answer : ALA synthase, aspartyl trans-carbamoylase, HMG CoA reductase
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 Competitive Inhibition -Biology
Last Answer : answer:
Description : What is non-competitive Inhibition? -Biology
Description : Difference between competitive and allosteric inhibition -Biology
Description : An example of competitive inhibition of an enzyme is the inhibition of a. Succinic dehydrogenase by malonic acid b. Cytochrome oxidase by cyanide c. Hexokinase by glucose-6-phosphate d. Carbonic anhydrase by carbon dioxide
Last Answer : Ans: A
Description : Photosynthetic inhibition by 02 is called: (A) Reaction (B) Warburg’s effect (C) Back inhibition (D) Competitive effect
Last Answer : (B) Warburg’s effect
Description : Which one of the following statements regarding enzyme inhibition is correct? (a) Competitive inhibition is seen when a substrate competes with an enzyme for binding to an inhibitor protein. (b ... large amount of substrate. (d) Non-competitive inhibitors often bind to the enzyme irreversibly.
Last Answer : (b) Competitive inhibition is seen when the substrate and the inhibitor compete for the active site on the enzyme
Description : Select the option which is not correct with respect to enzyme action. (a) Substrate binds with enzyme at its active site. (b) Addition of lot of succinate does not reverse the inhibition ... from that which binds the substrate. (d) Malonate is a competitive inhibitor of succinic dehydrogenase.
Last Answer : (b) Addition of lot of succinate does not reverse the inhibition of succinic dehydrogenase by malonate.
Description : Which one of the following statements is incorrect? (a) The competitive inhibitor does not affect the rate of breakdown of the enzyme-substrate complex. (b) The presence of the competitive inhibitor ... . (d) In competitive inhibition, the inhibitor molecule is not chemically changed by the enzyme.
Last Answer : (b) The presence of the competitive inhibitor decreases the Km of the enzyme for the substrate
Description : The sulfa drugs work by _______ with PABA in making folic acid. a. Positive Feedback b. Negative Feedback c. Competitive Inhibition d. Allosteric Inhibition
Last Answer : c. Competitive Inhibition
Description : What is it called when an enzyme is blocked at its active site so the normal substrate can't bind? a. Competitive Inhibition b. Feedback Inhibition c. Noncompetitive Inhibition d. Pathway Modulation
Last Answer : a. Competitive Inhibition
Description : If an enzyme‘s active site becomes deformed, inhibition was likely responsible. a. Metabolic b. Competitive c. Noncompetitive d. Cellular
Last Answer : c. Noncompetitive
Description : Clinical significance of competitive inhibitors -Biology
Description : What is the clinical application of fructose estimation in semen?
Last Answer : Fructose is secreted by seminal vesicles. A block in seminal vessels is indicated by the absence of fructose in semen.
Description : Give the clinical implications of these enzymes.
Last Answer : In infective hepatitis, ALT level is increased; in alcohol abuse, GGT level is increased; in obstructive jaundice, ALP level is increased.
Description : Choose the correct statement about topical NSAID preparations: A. They produce high drug levels in the blood by avoiding hepatic first pass metabolism B. They produce high drug levels in ... a strong placebo effect D. Interindividual variability in clinical response to these preparations is minimal
Last Answer : C. They elicit symptomatic relief in soft tissue rheumatism mainly by a strong placebo effect
Description : Choose the correct statement about nicotine: A. It selectively stimulates parasympathetic ganglia B. It has no clinical application C. It is used as an aid during smoking cessation D. It is used in Alzheimer's disease
Last Answer : C. It is used as an aid during smoking cessation
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
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
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
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
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 : Feedback inhibition of enzyme action is affected by (A) Enzyme (B) Substrate (C) End products (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