enzyme inhibition

Question 1

Define what a kenetically perfect enzyme is and why

Answer 1

An enzyme which has a Kcat/Km = 10^8 +
due to passive diffusion of substrate being 10^9

Question 2

For what reason are enzyme inhibitors importants

Answer 2

• Drugs, poisons, toxins
• Metabolic pathway control
• study enzyme mechanic
• study metabolic pathways

Question 3

What is a reversabe compaired to an irreversable enzyme

Answer 3

Irreversable:
- binds covalenbtly to the enzyme acitve site
- eaves enzyme perminetly disabled

Reversable:
- Binds to the enzyme
- can unbind leaving the enzyme in its natural state

Question 3

What is a compeditive inhibitor + example

Answer 3

Binds to the enzyme active site
compeate with substrate = mutually exculsive events
Lipitor = compeditive cholestrol inhibitor

Question 4

What is a non- compeditive inhibitor

Answer 4

One which binds allosterically to the enzyme
doesnt impact the rate of E+S bindning
impacts the enzymes affinity for the transition state

Question 5

What is the impact on kenetics of non-compeditive inhibition

Answer 5

• Lowers rate of process = lower Vmax
• doesnt affect affinity = no Km

lineweaver burk:
Km same x-int
Vmax = closer to infinite

Question 6

what is a mixed non-compeditive inhibitor

Answer 6

More realistic due to effects on substrate binding
- slightly impacts the binding to substrate when binding alloserically

Question 6

What is the impact on kenetics of compeditive inhibition

Answer 6

• doesnt effect Vmax as [S]»[I] will still reach
• lowers the Km = lower affinity

lineweaver burk:
Km closer to 0 = x int
Vmax same = yint