Quiz on Enzymes Three

Quiz on enzyme is back with more questions and more clues. On average your score should be around 75%.

1. What is covalent catalysis?
   • Formation of hydrogen bond between enzyme and substrate
   • Formation of covalent bond between enzyme and substrate
   • Formation of transient covalent bond between enzyme and substrate
   • None of the above
2. How metal ions participate in catalysis?
   • By causing reduction and oxidation reactions between enzyme and substrate
   • By causing ionic interactions between enzyme and substrate
   • All of the above
   • None of the above
3. What is the common enhancing rate of enzymes?
   • 105 to 1017
   • 1012 to 1020
   • 10-17 to 10-9
   • None of the above
4. Enzyme chymotrypsin carries out which type of catalysis?
   • Covalent catalysis
   • General acid base catalysis
   • None of the above
   • Both a and b
5. What is enzyme kinetics?
   • Studying the mechanism of rate of reaction of enzyme
   • Factors affecting enzyme activity
   • Both a and b
   • None of the above
6. What is Vmax?
   • Maximum rate of reaction
   • Rate of reaction increase with increase in enzyme concentration
   • Both a and b
   • None of the above
7. In which year, Victor Henri proposed that the combination of an enzyme with its substrate molecule to form an ES complex is necessary?
   • 1904
   • 1903
   • 1902
   • 1901
8. Who gave the general theory of enzyme action in 1913?
   • Leonor Michaelis and Maud Menten
   • Alfred Michaelis
   • Maud Michaelis
   • Leonor Menten and Maud Michaelis
9. In an enzyme catalyzed reaction, enzyme exists in which form?
   • Free form
   • Combined form
   • ES form
   • All of the above
10. The initial period when ES concentration builds up in an enzyme catalyzed reaction is called?
    • Steady state
    • Initial period
    • Pre steady state
    • Ephemeral state
11. The state which occurs after pre-steady state is called?
    • Pro-steady state
    • Late pre steady state
    • Post steady state
    • Steady state
12. Who introduced the concept of steady state kinetics in 1925?
    • G.E. Briggs and Haldane
    • Michaelis and Menten
    • Briggs
    • Menten
13. What is Km in Michaelis-Menten equation?
    • Michaelis-Menten constant
    • Substrate
    • Enzyme
    • All of the above
14. The initial reaction rate reflects a steady state in which [ES] is constant. This is called?
    • Michaelis and Menten state
    • Steady state assumption
    • Initial state assumption
    • None of the above
15. Which enzymes are said to follow Michaelis-Menten kinetics?
    • Enzymes which show parabolic dependence of rate of reaction and substrate
    • Enzymes which show circular dependence of rate of reaction and substrate
    • Enzymes which show hyperbolic dependence of rate of reaction and substrate
    • None of the above
16. Double-reciprocal plot is also called?
    • Michaelis plot
    • Line plot
    • Lineweaver-Burk plot
    • Inverse plot
17. What is Kd?
    • Dissociation constant
    • Michaelis constant
    • Lineweaver constant
    • None of the above
18. What is the unit of Kcat?
    • Reciprocal of concentration
    • Reciprocal of time
    • Both a and b
    • None of the above
19. Km and Kcat of an enzyme reflects?
    • Cellular environment
    • Concentration of substrate normally encountered in vivo
    • Reaction chemistry
    • None of the above
20. What is the Km of substrate whose concentration in cell is high?
    • Low
    • High
    • Depends on reaction
    • Depends on parameters

ANSWERS:

1. C
2. C
3. A
4. C
5. C
6. A
7. B
8. A
9. D
10. C
11. D
12. A
13. A
14. B
15. C
16. C
17. A
18. B
19. A, B, C
20. B