MCQOPTIONS

Explore topic-wise MCQs in Biochemistry.

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