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 : Maximum enzyme activity is observed at (A) Acidic pH (B) Neutral pH (C) Basic pH (D) Optimum pH
Last Answer : Answer : D
Description : Factors affecting enzyme activity: (A) Concentration (B) pH (C) Temperature (D) All of these
Description : The pH at which an enzyme has maximum activity is known as (A) Isoelectric pH (B) Optimum pH (C) Low pH (D) High pH
Last Answer : Answer : B
Description : Insulin has no effect on the activity of the enzyme: (A) Glycogen synthetase (B) Fructokinase (C) Pyruvate kinase (D) Pyruvate dehydrogenase
Description : In non competitive enzyme activity inhibition, inhibitor (A) Increases Km (B) Decreases Km (C) Does not effect Km (D) Increases Km
Description : How does pH affect enzyme activity? -Biology
Last Answer : answer:
Description : Activity of an enzyme can be modulated by change of – (1) pH (2) Light (3) Humidity (4) Rainfall
Last Answer : (1) pH Explanation: Changes in pH which can accompany metabolic process such as respiration (aerobic glycolysis for example) can alter the conformation of an enzyme and hence enzyme activity. The ... ) which can lead to an alteration in the delicate balance of forces that affect protein structure
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 : Pick out the wrong statement. (A) Catalytic activity of enzyme catalysed reactions which is affected by temperature, pH value & chemical agents, is maximum at a temperature of about 45°C ... in enzyme catalysed reactions can be calculated by using the thermodynamic properties of substrates & prod
Last Answer : (C) Enzymes help in increasing the activation energy of the reaction
Description : Activity of an enzyme can be modulated by change of (1) pH (2) Light (3) Humidity (4) Rainfall
Last Answer : pH
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 : 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 : The rate of most enzyme catalysed reactions changes with pH. As the pH increases, this rate (A) reaches a minimum, then increases (B) reaches a maximum, then decreases (C) increases (D) decreases
Description : In enzyme assays, all the following are kept constant except (A) Substrate concentration (B) Enzyme concentration (C) pH (D) Temperature
Description : Vmax of an enzyme may be affected by (A) pH (B) Temperature (C) Non-competitive inhibitors (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 : The optimal pH for the enzyme chymotrypsin is (A) 2.0 (B) 4.0 (C) 6.0 (D) 8.0
Description : The optimal pH for the enzyme trypsin is (A) 1.0–2.0 (B) 2.0–4.0 (C) 5.2–6.2 (D) 5.8–6.2
Description : The optimal pH for the enzyme rennin is (A) 2.0 (B) 4.0 (C) 8.0 (D) 6.0
Description : The optimal pH for the enzyme pepsin is (A) 1.0–2.0 (B) 4.0–5.0 (C) 5.2–6.0 (D) 5.8–6.2
Last Answer : Answer : A
Description : Which of the following is not true regarding enzymes? (A) They catalyze only a particular type of reaction (B) They remain active even after separation from the source (C) They are destroyed ... They are irreversibly destroyed at high temperature (E) Their activity depends on the pH of the solution
Description : What is the effect of substrate concentration on enzyme activity? -Biology
Description : Methotrexate blocks the synthesis of thymidine monophosphate by inhibiting the activity of the enzyme: (A) Dihydrofolate reductase (B) Orotate phosphoribosyl transferase (C) Ribonucleotide reductase (D) Dihydroorotase
Description : A deficiency of copper effects the formation of normal collagen by reducing the activity of which of the following enzyme? (A) Prolyl hydroxylase (B) Lysyl oxidase (C) Lysyl hydroxylase (D) Glucosyl transferase
Description : The deficiency of copper decreases the activity of the enzyme: (A) Lysine oxidase (B) Lysine hydroxylase (C) Tyrosine oxidase (D) Proline hydroxylase
Description : A cofactor required for the activity of the enzyme ALA dehydratase is (A) Cu (B) Mn (C) Mg (D) Fe
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 : An organic substance bound to an enzyme and essential for the activity of enzyme is called (A) Holoenzyme (B) Apoenzyme (C) Coenzyme (D) Isoenzyme
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 : Different isoenzymes of an enzyme have the same (A) Amino acid sequence (B) Michaelis constant (C) Catalytic activity (D) All of these
Description : An inorganic ion required for the activity of an enzyme is known as (A) Activator (B) Cofactor (C) Coenzyme (D) None of these
Description : In biosynthesis of cholesterol triparanol inhibits the activity of the enzyme: (A) ∆24 Reductase (B) Oxidosqualene-lanosterol cyclase (C) Isomerase (D) Squalene epoxidase ENZYMES 155
Description : The enzyme glycerol kinase is low activity in (A) Liver (B) Kidney (C) Intestine (D) Adipose tissue
Description : Dietary deficiency of thiamin inhibits the activity of the enzyme: (A) Pyruvate kinase (B) Pyruvate dehydrogenase (C) Phosphofructokinase (D) Enolase
Description : Lineweaver – Burk double reciprocal plot is related to (A) Substrate concentration (B) Enzyme activity (C) Temperature (D) Both (A) and (B) ENZYMES 145
Description : In glycolytic pathway, iodacetate inhibits the activity of the enzyme: (A) Phosphotriose isomerase (B) Glyceraldehyde-3-phosphate dehydrogenase (C) Pyruvate kinase (D) Phosphofructokinase
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 : Non steroidal anti inflammatory drugs, such as aspirin act by inhibiting the activity of the enzyme: (A) Lipoxygenase (B) Cyclooxygenase (C) Phospholipase A2 (D) Lipoprotein lipase
Description : Which one of the following statements concerning glucose-6-phosphate dehydrogenase deficiency is correct? (A) Young R.B.Cs, particularly reticulocytes, contain the highest enzyme activity cells show less enzyme ... PD gene (D) G-6-PD deficiency is precipitated by ingestion of drugs such as aspirin
Description : Aspirin inhibits the activity of the enzyme: (A) Lipoxygenase (B) Cyclooxygenase (C) Phospholipae A1 (D) Phospholipase A2
Description : The “Primaquin sensitivity types of haemolytic anaemia has been found to relate to reduced R.B.C activity of which enzyme? (A) Pyruvate kinase deficiency (B) Glucose-6-phosphatase deficiency (C) Glucose-6-p dehydrogenase deficiency (D) Hexokinase deficiency
Last Answer : C
Description : What are the different types of inhibitions of enzyme activity?
Last Answer : Competitive inhibition, non-competitive inhibition, suicide inhibition, and allosteric regulation.
Description : What is the explanation for the effect of pH?
Last Answer : The pH decides the charge on the amino acid residues at the active site. The net charge on the enzyme protein would influence substrate binding and catalytic activity.
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 kinetic effect of purely competitive inhibitor of an enzyme (A) Increases Km without affecting Vmax (B) Decreases Km without affecting Vmax (C) Increases Vmax without affecting Km (D) Decreases Vmax without affecting Km