Description : Feedback inhibition of enzyme is influenced by (A) Enzyme (B) External factors (C) End product (D) Substrate
Last Answer : Answer : C
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 : 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 : Which factor is responsible for inhibition of enzymatic process during feedback? (a) Substrate (b) Enzymes (c) End product (d) Temperature
Last Answer : (c) End product
Description : Feedback term refers to (A) Effect of substrate on rate of enzymatic reaction (B) Effect of end product on rate reaction (C) Effect of enzyme concentration on rate of reaction (D) Effect of external compound on rate of reaction
Last Answer : Answer : B
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 : 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
Last Answer : Answer : D
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 : A competitive inhibitor of an enzyme has which of the following properties? (A) It is frequently a feedback inhibitor (B) It becomes covalently attached to an enzyme (C) It decreases the Vmax (D) It interferes with substrate binding to the enzyme
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 : 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 : 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 : Allosteric enzymes regulate the formation of products by (A) Feedback inhibition (B) Non-competitive inhibition (C) Competitive inhibition (D) Repression-derepression
Description : If the substrate concentration is much below the km of the enzyme, the velocity of the reaction is (A) Directly proportional to substrate concentration (B) Not affected by enzyme concentration (C) Nearly equal to Vmax (D) Inversely proportional to substrate concentration
Description : The ability of CTP to bind to aspartate carbamoyltransferase and shut down the synthesis of more A- enzyme induction B- enzyme repression C- feedback inhibition of enzyme activity D- none of these
Last Answer : feedback inhibition of enzyme activity
Description : Which one of the following is the correct mathcing of the site of action on the given substrate, the enzyme acting upon it and the end producrt?
Last Answer : Which one of the following is the correct mathcing of the site of action on the given substrate, ... ( prop "Amylas")(rarr)` Disaccharie (Maltose)
Description : Which of the following is the correct matchin of the site of action on the given substrate, the enzyme acting state upon it and the end product
Last Answer : Which of the following is the correct matchin of the site of action on the given substrate, the ... alpha`-amylase `rarr` Disac- charide (Maltose)
Description : Which one of the following is the correct matching of the site of action on the given substrate, the enzyme acting upon it and the end product? (a) Small intestine : Proteins Pepsin → ... Trypsin → Monoglycerides (d) Small intestine : Starch α-Amylase → Disaccharide (maltose)
Last Answer : (d) Small intestine : Starch α-Amylase → Disaccharide
Description : Template/lock and key theory of enzyme action is supported by (A) Enzymes speed up reaction (B) Enzymes occur in living beings and speed up certain reactions (C) Enzymes determine the direction of reaction (D) Compounds similar to substrate inhibit enzyme activity
Description : Lock' and Key' model of enzyme action proposed by Fisher implies that (A) The active site is flexible and adjusts to substrate (B) The active site requires removal of PO4 group ( ... complementary in shape to that of the substrate (D) Substrates change conformation prior to active site interaction
Description : Fischer's lock and key' model of the enzyme action implies that (A) The active site is complementary in shape to that of substance only after interaction. (B) The active site is ... change conformation prior to active site interaction (D) The active site is flexible and adjusts to substrate
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 : 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 : An allosteric enzyme influences the enzyme activity by (A) Competiting for the catalytic site with the substrate (B) Changing the specificity of the enzyme for the substrate (C) Changing the conformation ... binding to a site other than catalytic site (D) Changing the nature of the products formed
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 : 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 : The inhibition of succinate dehydrogenase by malonate by (A) Competitive inhibition (B) Non-competitive inhibition (C) Uncompetitive inhibition (D) Feedback inhibition
Description : Allosteric inhibition is also known as (A) Competitive inhibition (B) Non-competitive inhibition (C) Feedback inhibition (D) None of these
Description : The antiviral action of amantadine is exerted through: A. Interaction with the viral M2 protein B. Interaction with a virus directed thymidine kinase C. Inhibition of a viral protease enzyme D. Inhibition of viral RNA mediated DNA synthesi
Last Answer : A. Interaction with the viral M2 protein
Description : Explain the process of digestion if a student puts a plain cracker in their mouth, chews it, and holds the mush in their mouth. Mention the pH, temperature, enzyme, substrate and products. ?
Last Answer : Part of the human body
Description : A specific fructokinase present in liver has a very high affinity for its substrate because (A) Km for fructose is very high (B) Km for fructose is very low (C) Activity is affected by fasting (D) Activity is affected by insulin
Description : Substrate concentration at which an enzyme attains half its maximum velocity is (A) Threshold value (B) Michaelis-Menton constant (C) Concentration level (D) None of these
Description : Km value of enzyme is substrate concentration at (A) ½ Vmax (B) 2 Vmax (C) ½ Vmax (D) 4 Vmax
Description : The ratio of enzyme to substrate molecules can be as low as (A) 1 : 100,000 (B) 1 : 500,000 (C) 1 : 10,000 (D) 1 : 1,000
Description : Combination of apoenzyme and coenzyme produces (A) Prosthetic group (B) Holoenzyme (C) Enzyme substrate complex (D) Enzyme product complex
Description : An enzyme promotes a chemical reaction by (A) Lowering the energy of activation (B) Causing the release of heat which acts as a primer (C) Increasing molecular motion (D) Changing the free energy difference between substrate and product
Description : The shape of an enzyme and consequently its activity can be reversibly altered from moment to moment by (A) Heat (B) Amino acid substrate (C) Allosteric subunits (D) Sulfur substitutions
Description : The rate of an enzyme catalyzed reaction was measured using several substrate concentrations that were much lower than Km, the dependence of reaction velocity on substrate concentration can best be ... constant fraction of Vmax (C) Equal to Km (D) Proportional to the substrate concentration
Description : The Michaelis constant, Km is (A) Numerically equal to ½ Vmax (B) Dependent on the enzyme concentration (C) Independent of pH (D) Numerically equal to the substrate concentration that gives half maximal velocity
Description : Enzymes activity is controlled by (A) pH of the solution (B) Temperature (C) Concentration of the enzyme (D) Concentration of the substrate (E) All of these
Description : When [s] is equal to Km, which of the following conditions exist? (A) Half the enzyme molecules are bound to substrate (B) The velocity of the reaction is equal to Vmax (C) The velocity of the reaction is independent of substrate concentration (D) Enzyme is completely saturated with substrate
Description : The Michaehis-Menten hypothesis: (A) Postulates the formation of an enzyme substrate complex (B) Enables us to calculate the isoelectric point of an enzyme (C) States that the ... independent of substrate concentration (D) States that the reaction rate is proportional to substrate concentration
Description : Velocity maximum for an enzyme at half the substrate concentration gives (A) The molecular weight of the enzyme (B) Km value (C) Isoelectric pH (D) Pk value
Description : A substrate for the enzyme aldolase is (A) galactose-6-phosphate (B) isocitric acid (C) Glucose-1-phosphate (D) Fructose 1, 6 diphosphate
Description : In enzyme assays, all the following are kept constant except (A) Substrate concentration (B) Enzyme concentration (C) pH (D) Temperature