MCQOPTIONS
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MCQOPTIONS
This section includes 82 Mcqs, each offering curated multiple-choice questions to sharpen your Enzymes Regulation knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
How many isomers do creatine kinase have? |
| A. | 2 |
| B. | 4 |
| C. | 5 |
| D. | None of the above |
| Answer» E. | |
| 52. |
Which of the following method alters the rate of enzymatic synthesis? |
| A. | Induction and repression |
| B. | Covalent modification |
| C. | Isoenzyme |
| D. | Non-covalent regulation of enzyme |
| Answer» B. Covalent modification | |
| 53. |
Isoenzymes differ in which of the following basis? |
| A. | Structure |
| B. | Function |
| C. | Kinetic property |
| D. | Both A and C |
| Answer» E. | |
| 54. |
Decreased synthesis of enzyme is known as ? |
| A. | Transcription |
| B. | Induction |
| C. | Translation |
| D. | Repression |
| Answer» E. | |
| 55. |
Increased synthesis of enzymes is known as ? |
| A. | Transcription |
| B. | Induction |
| C. | Translation |
| D. | Repression |
| Answer» C. Translation | |
| 56. |
Enzymes that are involved in the feedback inhibition are known as |
| A. | Apoenzymes |
| B. | Holoenzymes |
| C. | Allosteric enzymes |
| D. | Coenzymes |
| Answer» D. Coenzymes | |
| 57. |
The Lock and key theory of enzyme action was put forward by |
| A. | Koshland |
| B. | Fischer |
| C. | Kuhne |
| D. | Arrhenius |
| Answer» C. Kuhne | |
| 58. |
Blocking of enzyme action by blocking its active sites is |
| A. | feedback inhibition |
| B. | allosteric inhibition |
| C. | competitive inhibition |
| D. | non-competitive inhibition |
| Answer» D. non-competitive inhibition | |
| 59. |
Allosteric enzymes possess |
| A. | Three types of allosteric sites |
| B. | Active site and three types of allosteric sites |
| C. | Active site and two types of allosteric sites |
| D. | Active site and an allosteric site |
| Answer» E. | |
| 60. |
Allosteric enzymes consist of several |
| A. | polypeptide chains |
| B. | inhibitors |
| C. | temperature ranges |
| D. | active sites |
| Answer» B. inhibitors | |
| 61. |
Ribozymes are |
| A. | RNA acting as enzymes |
| B. | Ribose sugar acting as enzyme |
| C. | Antibodies acting as enzymes |
| D. | Protein acting as enzyme |
| Answer» B. Ribose sugar acting as enzyme | |
| 62. |
How does a noncomeptitive inhibitor affect an enzyme? |
| A. | Lowers the Michaelis constant of the enzyme |
| B. | Raises the Michaelis constant of the enzyme |
| C. | Lowers the maximum rate of the enzymatic reaction |
| D. | Raises the maximum rate of the enzymatic reaction |
| Answer» D. Raises the maximum rate of the enzymatic reaction | |
| 63. |
How is pepsinogen activated in the stomach? |
| A. | A portion is cleaved, activating the enzyme |
| B. | Cofactors bind to the enzyme, increasing its efficiency |
| C. | It is activated by the temperature change in the stomach lumen |
| D. | It is phosphorylated by another enzyme |
| Answer» B. Cofactors bind to the enzyme, increasing its efficiency | |
| 64. |
How do competitive inhibitors affect enzyme efficiency? |
| A. | Raise the maximum rate of the enzymatic reaction |
| B. | Raise the Michaelis constant |
| C. | Lower the Michaelis constant |
| D. | Lower the maximum rate of the enzymatic reaction |
| Answer» C. Lower the Michaelis constant | |
| 65. |
You have an enzyme solution and you add an inhibitor molecule and observe a marked decrease in enzyme activity. You increase the substrate concentration but this does not lead to any observable increase in enzyme activity. What can you conclude about your inhibitor? |
| A. | That it is a kinase |
| B. | That it is a competitive inhibitor |
| C. | That it is a noncompetitive inhibitor |
| D. | That is it an inorganic inhibitor |
| Answer» D. That is it an inorganic inhibitor | |
| 66. |
A researcher has designed a new type of inhibitor that binds at the active site of an enzyme. What type of inhibition does this molecule display? |
| A. | Uncompetitive inhibition |
| B. | Noncompetitive inhibition |
| C. | Competitive inhibition |
| D. | Suicide inhibition |
| Answer» D. Suicide inhibition | |
| 67. |
Which of the following choices describes a way to graphically determine the type of inhibition being displayed by an inhibitor? I. Plot initial reaction rate versus the concentration of substrate for the uninhibited enzyme, and then compare to the inhibited enzyme II. Plot the inverse of the initial reaction rate versus the inverse of the substrate concentration for the uninhibited enzyme, and then compare to the inhibited enzyme III. Plot the concentration of the inhibitor versus the concentration of substrate |
| A. | I and II |
| B. | II only |
| C. | I only |
| D. | I, II, and III |
| Answer» B. II only | |
| 68. |
Which of the following is an example of allosteric regulation of enzymes? |
| A. | The non-covalent binding of cAMP to the active site |
| B. | Phosphorylation of an amino acid somewhere other than the active site |
| C. | Phosphorylation of an amino acid in the active site |
| D. | The non-covalent binding of cAMP somewhere other than the active site |
| Answer» E. | |
| 69. |
Haemoglobin has _________ times affinity for CO than Oxygen |
| A. | 50 |
| B. | 100 |
| C. | 250 |
| D. | 320 |
| Answer» D. 320 | |
| 70. |
Which of the following promotes rouleaux formation |
| A. | Albumin |
| B. | Pre-albumin |
| C. | Fibrinogen |
| D. | Prothrombin |
| Answer» D. Prothrombin | |
| 71. |
Hypoproteinaemia produces oedema by |
| A. | Increasing hydrostatic pressure at capillary arteriolar end |
| B. | Increasing interstitial fluid osmotic pressure |
| C. | Decreasing colloidal osmotic pressure across the capillary wall |
| D. | All of the above |
| Answer» D. All of the above | |
| 72. |
Viscosity of blood increased with rise in ________ levels |
| A. | Albumin |
| B. | Globulin |
| C. | Fibrinogen |
| D. | Prothrombin |
| Answer» B. Globulin | |
| 73. |
Serum differs from plasma in that |
| A. | Serum is plasma minus fibrinogen and clotting factors |
| B. | Serum is clear, straw coloured fluid |
| C. | Serum has high histamine content |
| D. | All of the above |
| Answer» B. Serum is clear, straw coloured fluid | |
| 74. |
Normal blood pH is |
| A. | 7.3 |
| B. | 7.2 |
| C. | 7.4 |
| D. | 8.4 |
| Answer» D. 8.4 | |
| 75. |
Plasma represents ______% of total blood volume |
| A. | 35 |
| B. | 45 |
| C. | 55 |
| D. | 65 |
| Answer» C. 55 | |
| 76. |
Reversible covalent modification involves |
| A. | Activation of proenzymes |
| B. | Inhibition of proenzymes |
| C. | Denaturation of proenzymes |
| D. | None of the above |
| Answer» B. Inhibition of proenzymes | |
| 77. |
Amount of total blood volume in an individual is approximately- |
| A. | 50 ml/Kg body weight |
| B. | 60 ml/Kg body weight |
| C. | 90 ml/Kg body weight |
| D. | 80 ml/Kg body weight |
| Answer» E. | |
| 78. |
Which bond is not associated with Enzyme-substrate interaction - |
| A. | Hydrogen bonds |
| B. | Ionic bonds |
| C. | Di-sulfide bonds |
| D. | Van deer Waal s force of attraction |
| Answer» D. Van deer Waal s force of attraction | |
| 79. |
Thalasemia is characterized by |
| A. | Deficient production of and chains |
| B. | Defect in the polypeptide chains |
| C. | Normal globin genes |
| D. | All of the above |
| Answer» B. Defect in the polypeptide chains | |
| 80. |
Tissue macrophage system includes |
| A. | Alveolar macrophage in lungs |
| B. | Kuffer cells of the liver |
| C. | Osteoclast in bone |
| D. | All of the above |
| Answer» E. | |
| 81. |
Old RBCs are destroyed in |
| A. | Lungs |
| B. | Liver |
| C. | Spleen |
| D. | All of the above |
| Answer» E. | |
| 82. |
Most common form of Thalasemia is |
| A. | |
| B. | -major |
| C. | -minor |
| D. | |
| Answer» D. | |