Enzyme inhibition

Question 1

What is an inhibitor?

Answer 1

• sub. that reduces or eliminates the catalytic activity of an enzyme
• reduce/stop the reaction rate by combining with enzyme to form E-inhibitors complex

Question 2

@general description

Answer 2

Competitive
-close structural resemblance to the substrate

Non-com
-no close structural resemblance to the substrate

Question 3

Where it binds to?

Answer 3

Competitive
-competes with substrate molecule for active site, inhibiting the formation of ES complex

Non-com
-binds to a region OTHER than the active site, inducing the conformational change
-> alters the globular 3D structure and changes conformation of the active sire
=> unreceptive to the substrate, no catalysis taking place

Question 4

Method to overcome the inhibition?

Answer 4

Competitive
-increasing substrate concentration
-> increase the probability of ES collisions
=> rate of rn increased and effect of inhibition is negligible
-longer time to make the same amt of pdts

Non-comp
-cannot be reduced as it alters the 3D structure

Question 5

The effect on Vmax and Km

Answer 5

Competitive

• (V)unchanged
• (K)increases

Non-comp

• (V)lowered
• (K)remains unchanged

Question 6

How does enzyme inhibition works

Answer 6

Competitive:
Bound to active site;
Excludes substrate molecules;
Reduced rate of rn

Non-competitive:
alter 3D struct;
Altering confirmation of its active site;
Catalytic groups at active site changes;
Proportion of enzyme molecules out of action;
Lowering functional enzyme conce