Description : What is the effect of substrate concentration on enzyme activity? -Biology
Last Answer : answer:
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
Last Answer : Answer : C
Description : Lineweaver – Burk double reciprocal plot is related to (A) Substrate concentration (B) Enzyme activity (C) Temperature (D) Both (A) and (B) ENZYMES 145
Last Answer : Answer : D
Description : The curve given below shows enzymatic activity in relation to three conditions (pH, temperature and substrate concentration). What do the two axes (X and Y) represent? X-axis ... (b) Temperature Enzyme activity (c) Substrate Enzymatic concentration activity (d) Enzymatic activity Temperature
Last Answer : (b) Temperature Enzyme activity
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
Last Answer : Answer : B
Description : Km value of enzyme is substrate concentration at (A) ½ Vmax (B) 2 Vmax (C) ½ Vmax (D) 4 Vmax
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
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 : 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
Last Answer : Answer : A
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 : 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 : In enzyme assays, all the following are kept constant except (A) Substrate concentration (B) Enzyme concentration (C) pH (D) Temperature
Description : Competitive inhibition can be relieved by raising the (A) Enzyme concentration (B) Substrate concentration (C) Inhibitor concentration (D) None of these
Description : In enzyme kinetics Km implies (A) The substrate concentration that gives one half Vmax (B) The dissocation constant for the enzyme substrate comples (C) Concentration of enzyme (D) Half of the substrate concentration required to achieve Vmax
Description : In enzyme kinetics Vmax reflects (A) The amount of an active enzyme (B) Substrate concentration (C) Half the substrate concentration (D) Enzyme substrate complex
Description : Michaelis – Menten equation is used to explain the effect of substrate concentration on (A) Carbohydrate (B) Enzyme (C) Lipid (D) Protein
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 : 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 : 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 : 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 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 : Factors affecting enzyme activity: (A) Concentration (B) pH (C) Temperature (D) All of these
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 : At the adrenergic synapse, the concentration of adrenaline in synaptic cleft: a. increased by cocaine which inhibit reuptake of adrenaline b. decreased by MAO (monoamine oxidase) - inhibitors c. controlled chiefly by the activity of the enzyme COMT d. increased by noradrenaline receptor blockers
Last Answer : increased by cocaine which inhibit reuptake of adrenaline
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 : How an enzyme attaches to a substrate using the lock and key hypothesis?
Last Answer : What is the answer ?
Description : Where Do the Enzyme and substrate Bind?
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 : 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 : 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 : Combination of apoenzyme and coenzyme produces (A) Prosthetic group (B) Holoenzyme (C) Enzyme substrate complex (D) Enzyme product complex
Description : Feedback inhibition of enzyme action is affected by (A) Enzyme (B) Substrate (C) End products (D) None of these
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 : 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 : 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 : 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 : 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 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 : An allosteric enzyme is generally inhibited by (A) Initial substrate of the pathway (B) Substrate analogues (C) Product of the reaction catalysed by allosteric enzyme (D) Product of the pathway
Description : The hypothesis to explain enzyme– substrate complex formation: (A) Lock and key model (B) Induced fit theory (C) Proenzyme theory (D) Both (A) and (B)
Description : Example of enzyme specificity: (A) Stereo specificity (B) Reaction specificity (C) Substrate specificity(D) All of these
Description : If all the enzymes, intermediates and cofactors of the citric acid cycle as well as an excess of the starting substrate acetylCoA are present and functional in an organelle free solution at the appropriate ... oxygen (B) Half life of enzyme (C) Turnover of intermediates (D) Reduction of cofactors
Description : An enzyme which uses hydrogen acceptor as substrate is (A) Xanthine oxidase (B) Aldehyde oxidase (C) Catalase (D) Tryptophan oxygenase
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 : Regulator gene controls chemical synthesis (Operon concept) by (a) Inhibiting transcription of mRNA (b) Inhibiting enzymes (c) Inhibiting passage of mRNA (d) Inhibiting substrate enzyme reaction
Last Answer : Ans. ((a))