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 of succinic dehydrogenase by
malonate.
(c) A non-competitive inhibitor binds the enzyme
at a site distinct from that which binds the
substrate.
(d) Malonate is a competitive inhibitor of succinic
dehydrogenase.

1 Answer

Answer :

(b) Addition of lot of succinate does not reverse
the inhibition of succinic dehydrogenase by
malonate.

Related questions

Description : The inhibition of succinate dehydrogenase by malonate by (A) Competitive inhibition (B) Non-competitive inhibition (C) Uncompetitive inhibition (D) Feedback inhibition

Last Answer : Answer : A

Description : A competitive inhibitor of succinic dehydrogenase is (a) α-ketoglutarate (b) malate (c) malonate (d) oxaloacetate.

Last Answer : (c) malonate

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 : 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 : A specific inhibitor for succinate dehydrogenase is (A) Arsenite (B) Malonate (C) Citrate (D) Fluoride

Last Answer : Answer : B

Description : Malonate is an inhibitor of (A) Malate dehydrogenase (B) α-Ketoglutarate dehydrogenase (C) Succinate dehydrogenase (D) Isocitrate dehydrogenase

Last Answer : Answer : C

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 : 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

Last Answer : Answer : B

Description : A substance unrelated to substrate but capable of reversibly changing activity of enzyme by binding to a site other than active site is called (a) Competitive inhibitor (b) Non-competitive inhibitor (c) Catalytic inhibitor (d) Allosteric modulator/inhibitor

Last Answer : Ans. ((d))

Description : Competitive inhibition can be relieved by raising the (A) Enzyme concentration (B) Substrate concentration (C) Inhibitor concentration (D) None of these

Last Answer : Answer : B

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

Last Answer : Answer : A

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 : 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 : 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

Last Answer : Answer : A

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 : 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 : Which inactivates an enzyme by occupying its active site? (A) Competitive inhibitor (B) Allosteric inhibitor (C) Non-competitive inhibitor (D) All of these

Last Answer : Answer : A

Description : What happens to an enzyme when a competitive inhibitor binds to it?

Last Answer : Need answer

Description : Active transport of sugar is depressed by the agent: (A) Oxaloacetate (B) Fumarate (C) Malonate (D) Succinate

Last Answer : C

Description : Match the following. (A) Inhibitor of (i) Ricin catalytic activity (B) Possess peptide (ii) Malonate bonds (C) Cell wall material (iii)Chitin in fungi (D) Secondary (iv) Collagen metabolite Choose the correct option from the following: (A) ... iv) (ii) (c) (iii) (iv) (i) (ii) (d) (ii) (iii) (i) (iv)

Last Answer : (A) Inhibitor of (i) Ricin catalytic activity

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

Last Answer : Answer : D

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 : Substrate level phosphorylation in TCA cycle is in step: (A) Isocitrate dehydrogenase (B) Malate dehydrogenase (C) Aconitase (D) Succinate thiokinase

Last Answer : D

Description : A specific inhibitor for succinate dehydrogenase is (A) Arsenine (B) Arsenite (C) Citrate (D) Fluoride ENZYMES 147

Last Answer : Answer : B

Description : A specific inhibitor for succinate dehydrogenase is (A) Arsinite (B) Melouate (C) Citrate (D) Cyanide

Last Answer : B

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

Last Answer : Answer : D

Description : The following inhibitor binds only to the ani-onic site of the cholinesterase enzyme: A. Neostigmine B. Physostigmine C. Edrophonium D. Dyflos

Last Answer : C. Edrophonium

Description : The following inhibitor binds only to the ani-onic site of the cholinesterase enzyme: A. Neostigmine B. Physostigmine C. Edrophonium D. Dyflos

Last Answer : C. Edrophonium

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 : Feedback inhibition of enzyme action is affected by (A) Enzyme (B) Substrate (C) End products (D) None of these

Last Answer : Answer : C

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

Last Answer : Answer : C

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

Last Answer : Answer : B

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

Last Answer : Answer : C

Description : A mitochondrial marker enzyme is (A) Aldolase (B) Amylase (C) Succinic dehydrogenase (D) Pyruvate dehydrogenase ENZYMES 175

Last Answer : Answer : C

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 : Calcium is required for the activation of the enzyme: (A) Isocitrate dehydrogenase (B) Fumarase (C) Succinate thiokinase (D) ATPase

Last Answer : Answer : D

Description : Zinc is a constituent of the enzyme: (A) Succinate dehydrogenase (B) Carbonic anhydrase (C) Mitochondrial superoxide dismutase (D) Aldolase

Last Answer : Answer : B

Description : The enzyme using some other substance, not oxygen as hydrogen acceptor is (A) Tyrosinase (B) Succinate dehydrogenase (C) Uricase (D) Cytochrome oxidase

Last Answer : Answer : B

Description : An enzyme catalyzing oxidoreduction, using oxygen as hydrogen acceptor is (A) Cytochrome oxidase (B) Lactate dehydrogenase (C) Malate dehydrogenase (D) Succinate dehydrogenase

Last Answer : Answer : A

Description : NADPH is produced when this enzyme acts (A) Pyruvate dehydrogenase (B) Malic enzyme (C) Succinate dehydrogenase (D) Malate dehydrogenase

Last Answer : Answer : B

Description : All enzymes of TCA cycle are located in the mitochondrial matrix except one which is located in inner mitochondrial membranes in eukaryotes and in cytosol in prokaryotes. This enzyme is (a) isocitrate dehydrogenase (b) malate dehydrogenase (c) succinate dehydrogenase (d) lactate dehydrogenase.

Last Answer : (c) succinate dehydrogenase

Description : In non-competitive enzyme action (A) Vmax is increased (B) Apparent km is increased (C) Apparent km is decreased (D) Concentration of active enzyme molecule is reduced

Last Answer : Answer : C

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

Last Answer : Answer : A

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

Last Answer : Answer : A

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 : Feedback inhibition of enzyme is influenced by (A) Enzyme (B) External factors (C) End product (D) Substrate

Last Answer : Answer : C

Description : The high virus selectivity of acyclovir is due to: A. Its preferential uptake by virus infected cells B. Need of virus specific enzyme for its conversion to the active metabolite C. Its action on ... reverse transcriptase which does not occur in noninfected cells D. Both A' and B' are correct

Last Answer : D. Both ‘A’ and ‘B’ are correct

Description : Which of the following is a specific inhibitor of the enzyme alcohol dehydrogenase and is useful in the treatment of methanol poisoning: A. Disulfiram B. Ethylene glycol C. Calcium leucovorin D. Fomepizole

Last Answer : D. Fomepizole