MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 79 Mcqs, each offering curated multiple-choice questions to sharpen your Enzyme Science knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
A DNA fragment of 4500 bp has to be tailed with dT residues by using dTTP and the enzyme terminal transferase . The stock solution of dTTP that is used as a substrate has a concentration of 150 M. Ten l of this stock solution is added to a total volume of 200 l reaction. What will be the concentration of dTTP in the reaction? |
| A. | 7.5 M |
| B. | 75 M |
| C. | 0.75 M |
| D. | 0.075 M |
| Answer» B. 75 M | |
| 52. |
Which of the following techniques is best suited for immobilizing an affinity ligand? |
| A. | Physical adsorption |
| B. | Gel entrapment |
| C. | Cross-linking with a polymer |
| D. | Covalent linkage to a spacer arm |
| Answer» E. | |
| 53. |
One unit of glucoamylase enzyme activity is defined as the amount of enzyme required to produce (imol of glucose per min in a 4% solution of Lintner starch at pH 4.5 and 60 C. If in a reaction mixture with 1ml of the crude enzyme preparation containing 8 mg protein and 9 ml of 4.44% starch, 0.6 mc of glucose/ml-min is produced, what will be the specific activity of the crude enzyme preparation? |
| A. | 1 unit/mg protein |
| B. | 1.5 units/mg protein |
| C. | 0.25 units/mg protein |
| D. | 0.75 units/mg protein |
| E. | None of these |
| Answer» F. | |
| 54. |
The respective values of the Monod kinetic constants m (hr |
| A. | 0.08, 8 |
| B. | 0.8, 0.8 |
| C. | 0.8, 80 |
| D. | 8, 8 |
| Answer» D. 8, 8 | |
| 55. |
After completion of Nick translation reaction, 10 l of reaction was spotted on a glass-fiber filter that upon counting resulted into 4.2 10 |
| A. | 40% |
| B. | 50% |
| C. | 60% |
| D. | 70% |
| Answer» E. | |
| 56. |
The maximum possible conversion for the enzymatic reaction will be |
| A. | 100% |
| B. | 50% |
| C. | 25% |
| D. | 12.5% |
| E. | NA |
| Answer» F. | |
| 57. |
Which one of the following reactions is used for the purpose of recycling enzymes inbioprocesses ? |
| A. | Isomerization |
| B. | Immobilization |
| C. | Phosphorylation |
| D. | Polymerization |
| Answer» C. Phosphorylation | |
| 58. |
Enzyme papain is used with success to |
| A. | increase meat production |
| B. | leaven bread |
| C. | ripen papaya fruit |
| D. | tenderize meat |
| Answer» E. | |
| 59. |
The time required to convert 10% of the substrate will be rapproximately |
| A. | 16 min |
| B. | 24 min |
| C. | 32 min |
| D. | 8 min |
| E. | NA |
| Answer» F. | |
| 60. |
Therefore the lac-operon is |
| A. | repressed and can only be induced with lactose. |
| B. | repressed and cannot be induced with lactose. |
| C. | not repressed. |
| D. | expressed only when glucose and lactose are present. |
| Answer» C. not repressed. | |
| 61. |
The molar concentration of the repressor in the cell is |
| A. | 1.1 nM |
| B. | 1 nM |
| C. | 10 nM |
| D. | 100 nM |
| Answer» E. | |
| 62. |
The yield (%) for each step is |
| A. | P 10, Q 7.2, R 4.5, S 2.0 |
| B. | P 34, Q 24, R 15, S 1 |
| C. | P 3.4, Q 2.4, R 1.5, S 0.1 |
| D. | P 100, Q 71, R 44, S 29 |
| Answer» E. | |
| 63. |
The fold purification for each step is |
| A. | P 0.1, Q 0.66, R 0.84, S 1.26 |
| B. | P 1.0, Q 0.52, R 0.67, S 0.8 |
| C. | P 1, Q 6.6, R 8.4, S 12.6 |
| D. | P 100, Q 66, R 84, S 12 |
| Answer» D. P 100, Q 66, R 84, S 12 | |
| 64. |
Match the industrial application of the following enzymes |
| A. | P-4 P-l P-l P-4 |
| B. | Q-3 Q-3 Q-2 Q-2 |
| C. | R-l R-2 R-3 R-3 |
| D. | S-2 S-4 S-4 S-l |
| Answer» C. R-l R-2 R-3 R-3 | |
| 65. |
Triose phosphate isomerase converts dihydroxy acetone phosphate (DHAP) to glyceraldehyde-3-phosphate (G-3-P) in a reversible reaction. At 298 K and pH 7.0, the equilibrium mixture contains 40 mM DHAP and 4 mM G-3-P. Assume that the reaction started with 44 mM DHAP and no G-3-P. The standard free-energy change in kJ/mol for the formation of G-3-P [R = 8.315 J/mol.K] is _________. |
| A. | 3.55 to 3.70 |
| B. | 2.46 to 2.50 |
| C. | 4.95 to 5.00 |
| D. | 7.35 to 7.40 |
| Answer» C. 4.95 to 5.00 | |
| 66. |
The degree of reduction of ethanol is _______ |
| A. | 1 to 1 |
| B. | 3 to 3 |
| C. | 4 to 4 |
| D. | 6 to 6 |
| Answer» E. | |
| 67. |
The percent inhibition for this enzyme is calculated from the equation |
| A. | {[cpm (control) cpm (test)]/[cpm (control) cpm (blank)]} 100 |
| B. | {[cpm (control) cpm (test)]/[cpm(blank) cpm (control)])} 100 |
| C. | {[cpm (test) cpm (control)]/[cpm (control) cpm (blank)])} 100 |
| D. | {[cpm (control) cpm (blank)]/[cpm (test) cpm (control)])} 100 |
| Answer» B. {[cpm (control) cpm (test)]/[cpm(blank) cpm (control)])} 100 | |
| 68. |
The degree of inhibition for non-competitive inhibition of an enzyme catalyzed reaction |
| A. | Increases with increases in substrate concentration |
| B. | Reaches a maxima with increase in substrate concentration and then decreases |
| C. | Is independent of substrate concentration |
| D. | Decreases with increase in substrate concentration |
| Answer» D. Decreases with increase in substrate concentration | |
| 69. |
An inhibitor is considered active if it causes more than 65% inhibition. The. cpm Values respectively of control, test and blank samples for inhibitors W, X, Y and Z are given below. State which of the inhibitors is active. |
| A. | X 8000, 4000 and 100 |
| B. | W 7000, 1400 and 135 |
| C. | Y 7500, 5000 and 90 |
| D. | Z 7200, 2800 and 200 |
| Answer» C. Y 7500, 5000 and 90 | |
| 70. |
Which of the following techniques is NOT ideal for immobilizing cell-free enzymes ? |
| A. | physical entrapment by encapsulation |
| B. | covalent chemical bonding to surface carriers |
| C. | physical bonding by flocculation |
| D. | covalent chemical bonding by cross-linking the precipitate |
| Answer» E. | |
| 71. |
The following culture systems are used for growing large amount of anchorage dependent animal cells except |
| A. | Roller bottle |
| B. | Airlift fermenter |
| C. | Hollow fibre reactor |
| D. | Microcarrieres |
| Answer» C. Hollow fibre reactor | |
| 72. |
The following cross-linking agents may be used for the immobilization of enzymes |
| A. | Glutaraldehyde |
| B. | Cyanogen bromide |
| C. | Thionyl chloride |
| D. | All of these |
| Answer» E. | |
| 73. |
The typical coenzyme present in the methanogenes is |
| A. | Coenzyme A |
| B. | Coenzyme Q |
| C. | Coenzyme M |
| D. | None of these |
| Answer» D. None of these | |
| 74. |
Ethanol concentration is lowest in |
| A. | Wine |
| B. | Beer |
| C. | Brandy |
| D. | Rum |
| Answer» C. Brandy | |
| 75. |
A chemostat is operating at steady state at a dilution rate of 0.1 hr |
| A. | Abzyme is a monoclonal antibody with catalytic activity. Abzymes are usually artificial constructs, but are also found in normal and in patients with autoimmune diseases such as systemic lupus erythematosus, where they can bind to and hydrolyze DNA. |
| B. | Enzyme is a monoclonal antibody with catalytic activity. Abzymes are usually artificial constructs, but are also found in normal and in patients with autoimmune diseases such as systemic lupus erythematosus, where they can bind to and hydrolyze DNA. |
| C. | Both A and B |
| D. | None of the above |
| Answer» B. Enzyme is a monoclonal antibody with catalytic activity. Abzymes are usually artificial constructs, but are also found in normal and in patients with autoimmune diseases such as systemic lupus erythematosus, where they can bind to and hydrolyze DNA. | |
| 76. |
Which of the following cases are likely to lead to faster rates of catalysis by an enzyme immobilized on a negatively charged support? |
| A. | A positively charged substrate and a negatively charged product |
| B. | A negatively charged substrate and a positively charged product |
| C. | A positively charged substrate and a positively charged product |
| D. | All of the above |
| E. | None of the above |
| Answer» B. A negatively charged substrate and a positively charged product | |
| 77. |
The Pasteur Effect is |
| A. | Inhibition of glucose utilization and lactate accumulation in glycolysis |
| B. | Sterilisation of milk |
| C. | Vaccine production |
| D. | Heat treament of bacteria |
| Answer» E. | |
| 78. |
Which one of the following is not a protease ? |
| A. | Proteosome |
| B. | Trypsin |
| C. | Chrymotrypsin |
| D. | Peptidyl tRNA hydrolase |
| Answer» C. Chrymotrypsin | |
| 79. |
Abzymes are |
| A. | Enzymes that are highly specific like antibodies |
| B. | Antibodies that have catalytic activities |
| C. | Also referred to as zymogens |
| D. | Enzymes which hydrolyze antibodies |
| Answer» C. Also referred to as zymogens | |