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 non competitive enzyme activity inhibition, inhibitor (A) Increases Km (B) Decreases Km (C) Does not effect Km (D) Increases Km
Last Answer : Answer : C
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
Last Answer : Answer : A
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
Last Answer : Answer : B
Description : Of Which warburg’s yellow enzyme contains as a prosthetic group? (A) Thiamine pyrophosphate (B) Biotin (C) NAD+ (D) Riboflavin-5-phosphate
Description : The size of clay particles are— (A) 1•0 mm (B) 0•2 – 0•02 mm (C) < 0•02 mm (D) < 0•002 mm
Last Answer : (D) < 0•002 mm
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 : What is Competitive Inhibition -Biology
Last Answer : answer:
Description : What is non-competitive Inhibition? -Biology
Description : Difference between competitive and allosteric inhibition -Biology
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 : 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 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 : 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 : 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 : 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 : 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 : 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 : The path of `CO_(2)` in the dark reaction of photosynthetic was successfully traced by the use of the following or The dark reaction is traced by
Last Answer : The path of `CO_(2)` in the dark reaction of photosynthetic was successfully traced by the use of the following or ... O_(2)` C. `P^(32)` D. X-rays
Description : Carbon dioxide joins the photosynthetic pathway in (a) PS I (b) PS II (c) light reaction (d) dark reaction
Last Answer : d) dark reaction.
Description : Inhibition of photosynthesis in the presence of O2 in C3 plants is called- (1) Hexose monophosphate shunt (2) Pasteur effect (3) Decker effect (4) Warburg effect
Last Answer : (4) Warburg effect Explanation: An increase in the oxygen concentration in many plants results in a decrease in the rate of photosynthesis. This phenomenon of the inhibition of photosynthesis by O2 was first ... known to occur in C3 plants (Soyabean) and C4 plants (Sorghum, Maize, Sugarcane), etc.
Description : Inhibition of photosynthesis in the presence of O2 in C3 plants is called : (1) Hexose monophosphate shunt (2) Pasteur effect (3) Decker effect (4) Warburg effect
Last Answer : Warburg effect
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 : 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 primary action by which entacapone and tolcapone enhance the therapeutic effect of levodopa-carbidopa in parkinsonism is: A. Inhibition of levodopa methylation in the liver B. Inhibition of ... of dopamine in the brain D. Facilitation of active transport of levodopa across brain capillaries
Last Answer : A. Inhibition of levodopa methylation in the liver
Description : The following effect(s) of tamoxifen citrate indicate(s) that it possesses tissue specific estrogenic action as well: A. Inhibition of breast cancer cells B. Endometrial proliferation C. Hot flushes in premenopausal women D. All of the above
Last Answer : B. Endometrial proliferation
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 : Most commonly employed test for determining the antibody titers for Newcastle disease infection in B A. Agar gel precipitation test B. Hemagglutination inhibition C. Polymerase chain reaction D. None of these
Last Answer : Hemagglutination inhibition
Description : Most commonly employed test for determining the antibody titers for AI infection is B A. Agar gel precipitation test B. Hemagglutination inhibition C. Polymerase chain reaction D. None of these
Description : When antigens are attached to the surface of latex beads and then reacted with an appropriate antibody, a/an reaction occurs. a. Inhibition b. Agglutination c. Neutralization d. Precipitation
Last Answer : b. Agglutination
Description : Theophylline is believed to benefit asthma patients by exerting the following actions except: A. Bronchodilatation B. Augmentation of diaphragmatic contractility C. Reduced mediator release D. Inhibition of antigen: antibody reaction
Last Answer : D. Inhibition of antigen: antibody reaction
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 : 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 : Impect of green house effect is: (A)Global warming (B) Ice melting (C) Sea formation (D) Sea level rise
Last Answer : (A)Global warming