Biochemistry
Enzyme Inhibition
Compiled By Simon Mwangi
Edition: 2024/25
, Science | Biochemistry I of IV pages
1. Two main categories/classes of inhibitors
Irreversibel Reversible
2. Definition of inhibitors
Molecules that interfere with catalysis, slowing or halting enzymatic reactions
3. 3 types of reversible inhibitors
Competitive UncompetitiveNoncompetitive
4. Difference between uncompetitive and noncompetitive inhibition
Uncompetitive binds only when the substrate is bound and it binds to additional binding site on active
5. When does the uncompetitive inhibitor bind?
Only after substrate is bound
6. When does the noncompetitive inhibitor bind?
In all conditions, substrat bound or not bound
7. What does sulphanilamide mimic the structure of? and thus inhibits the metabolisation of
PABA (p-aminobenzoic acid)
8. How is the rate of reaction effected by the inhibitor?
The rate decreasesDue to decrease in affinity More substrate is needed
9. What is Km?
Substrate concentration at half Vmax
10. What happens to the Vmax during competitive inhibition?
NothingIt is not changing because as substrate increases inhibition decreases eventually to the point where it
11. What happens to the Km during competitive inhibition?
Increases
12. Does competitive inhibition affect catalysis?
No, does not effect the catalysis and the process
13. With competitive inhibitors how do the Vmax compare to reaction with no inhibitor?
They are the same
14. In a noncompetitive inhibitor how is the Km effected?
No changeBecause the binding site is the same and the binding is the same (affinity for binding is the same)
15. In a noncompetitive inhibitor how is the Vmax effected?
Decrease Activity of enzyme is decreased
16. What does the noncompetitive inhibitor affect? The affinity to bind or the enzymatic activity?
Enzymatic activity
Biochemistry 2024/25 Edition
Enzyme Inhibition
Compiled By Simon Mwangi
Edition: 2024/25
, Science | Biochemistry I of IV pages
1. Two main categories/classes of inhibitors
Irreversibel Reversible
2. Definition of inhibitors
Molecules that interfere with catalysis, slowing or halting enzymatic reactions
3. 3 types of reversible inhibitors
Competitive UncompetitiveNoncompetitive
4. Difference between uncompetitive and noncompetitive inhibition
Uncompetitive binds only when the substrate is bound and it binds to additional binding site on active
5. When does the uncompetitive inhibitor bind?
Only after substrate is bound
6. When does the noncompetitive inhibitor bind?
In all conditions, substrat bound or not bound
7. What does sulphanilamide mimic the structure of? and thus inhibits the metabolisation of
PABA (p-aminobenzoic acid)
8. How is the rate of reaction effected by the inhibitor?
The rate decreasesDue to decrease in affinity More substrate is needed
9. What is Km?
Substrate concentration at half Vmax
10. What happens to the Vmax during competitive inhibition?
NothingIt is not changing because as substrate increases inhibition decreases eventually to the point where it
11. What happens to the Km during competitive inhibition?
Increases
12. Does competitive inhibition affect catalysis?
No, does not effect the catalysis and the process
13. With competitive inhibitors how do the Vmax compare to reaction with no inhibitor?
They are the same
14. In a noncompetitive inhibitor how is the Km effected?
No changeBecause the binding site is the same and the binding is the same (affinity for binding is the same)
15. In a noncompetitive inhibitor how is the Vmax effected?
Decrease Activity of enzyme is decreased
16. What does the noncompetitive inhibitor affect? The affinity to bind or the enzymatic activity?
Enzymatic activity
Biochemistry 2024/25 Edition
