MCQOPTIONS
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MCQOPTIONS
This section includes 18 Mcqs, each offering curated multiple-choice questions to sharpen your Biochemistry knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
What is the general mechanism of an enzyme? |
| A. | It acts by reducing the activation energy |
| B. | It acts by increasing the activation energy |
| C. | It acts by decreasing the pH |
| D. | It acts by increasing the pH |
| Answer» B. It acts by increasing the activation energy | |
| 2. |
The catalytic efficiency of two distinct enzymes can be compared based on which of the following factor? |
| A. | Km |
| B. | Product formation |
| C. | Size of the enzymes |
| D. | pH of optimum value |
| Answer» B. Product formation | |
| 3. |
Where does inhibitor binds on enzyme in mixed inhibition? |
| A. | At active site |
| B. | Allosteric site |
| C. | Does not bind on enzyme |
| D. | Binds on substrate |
| Answer» C. Does not bind on enzyme | |
| 4. |
Which of the following is an example of reversible inhibitor? |
| A. | DIPF |
| B. | Penicillin |
| C. | Iodoacetamide |
| D. | Protease inhibitors |
| Answer» E. | |
| 5. |
The molecule which acts directly on an enzyme to lower its catalytic rate is __________ |
| A. | Repressor |
| B. | Inhibitor |
| C. | Modulator |
| D. | Regulator |
| Answer» C. Modulator | |
| 6. |
The rate determining step of Michaelis-Menten kinetics is __________ |
| A. | The complex dissociation step to produce products |
| B. | The complex formation step |
| C. | The product formation step |
| D. | None of the mentioned |
| Answer» B. The complex formation step | |
| 7. |
Which of the following statements is true about uncompetitive inhibitors? |
| A. | They bind covalently at a site distinct from the substrate active site |
| B. | In the presence of a uncompetitive inhibitor, the Michaelis-Menten equation becomes\(V_0 = \frac{V_{max} [S]}{K_m+α’ [S]} \) |
| C. | They increase the measured Vmax |
| D. | Apparent Km also increases |
| Answer» C. They increase the measured Vmax | |
| 8. |
Which of the following statements is true about competitive inhibitors? |
| A. | It is a common type of irreversible inhibition |
| B. | In the presence of a competitive inhibitor, the Michaelis-Menten equation becomes\(V_0 = \frac{V_{max} [S]}{α K_m+[S]} \) |
| C. | The apparent Km decreases in the presence of inhibitor by a factor α |
| D. | The maximum velocity for the reaction decreases in the presence of a competitive inhibitor |
| Answer» C. The apparent Km decreases in the presence of inhibitor by a factor α | |
| 9. |
Which of the following is the correct Line weaver-Burk equation? |
| A. | \(\frac{1}{V_0} = \frac{K_m}{V_{max} [S]} + \frac{1}{V_{max}} \) |
| B. | \(\frac{1}{V_{max}} = \frac{K_m}{V_0 [S]} + \frac{1}{V_0} \) |
| C. | \(V_0 = \frac{V_{max} [S]}{K_m+[S]} \) |
| D. | \(V_{max} = \frac{V_0 [S]}{K_m+[S]} \) |
| Answer» B. \(\frac{1}{V_{max}} = \frac{K_m}{V_0 [S]} + \frac{1}{V_0} \) | |
| 10. |
WHICH_OF_THE_FOLLOWING_IS_AN_EXAMPLE_OF_REVERSIBLE_INHIBITOR??$ |
| A. | DIPF |
| B. | Penicillin |
| C. | Iodoacetamide |
| D. | Protease inhibitors |
| Answer» E. | |
| 11. |
The catalytic efficiency of two distinct enzymes can be compared based on which of the following factor?$ |
| A. | K<sub>m</sub> |
| B. | Product formation |
| C. | Size of the enzymes |
| D. | pH of optimum value |
| Answer» B. Product formation | |
| 12. |
Where_does_inhibitor_binds_on_enzyme_in_mixed_inhibition?$ |
| A. | At active site |
| B. | Allosteric site |
| C. | Does not bind on enzyme |
| D. | Binds on substrate |
| Answer» C. Does not bind on enzyme | |
| 13. |
What_is_the_general_mechanism_of_an_enzyme? |
| A. | It acts by reducing the activation energy |
| B. | It acts by increasing the activation energy |
| C. | It acts by decreasing the pH |
| D. | It acts by increasing the pH |
| Answer» B. It acts by increasing the activation energy | |
| 14. |
Which of the following is an example for irreversible inhibitor? |
| A. | Disulfiram |
| B. | Oseltamivir |
| C. | Protease inhibitors |
| D. | DIPF |
| Answer» E. | |
| 15. |
The molecule which acts directly on an enzyme to lower its catalytic rate is |
| A. | Repressor |
| B. | Inhibitor |
| C. | Modulator |
| D. | Regulator |
| Answer» C. Modulator | |
| 16. |
The rate determining step of Michaelis-Menten kinetics is |
| A. | The complex dissociation step to produce products |
| B. | The complex formation step |
| C. | The product formation step |
| D. | None of the above |
| Answer» B. The complex formation step | |
| 17. |
When the velocity of enzyme activity is plotted against substrate concentration, which of the following is obtained? |
| A. | Hyperbolic curve |
| B. | Parabola |
| C. | Straight line with positive slope |
| D. | Straight line with negative slope |
| Answer» B. Parabola | |
| 18. |
Which of the following is true about Michaelis-Menten kinetics? |
| A. | K<sub>m</sub>, the Michaelis constant, is defined as that concentration of substrate at which enzyme is working at maximum velocity |
| B. | It describes single substrate enzymes |
| C. | K<sub>m</sub>, the Michaelis constant is defined as the dissociation constant of the enzyme-substrate complex |
| D. | It assumes covalent binding occurs between enzyme and substrate |
| Answer» C. K<sub>m</sub>, the Michaelis constant is defined as the dissociation constant of the enzyme-substrate complex | |