Enzyme Inhibitors Flashcards
How can enzymes be activated?
By cofactors
How can enzymes be deactivated?
By inhibitors
What is an inhibitor?
Any molecule that reduces or stops a reaction
What happens if you add a small concentration of an inhibitor?
It will reduce the rate of reaction
What happens if you add a small concentration of an inhibitor?
The reaction may be prevented completely
What are the 2 types of inhibitors?
Competitive inhibitors
Non-competitive inhibitors
Competitive inhibitors
Where do competitive inhibitors fit into instead of the substrate?
The active site of an enzyme
Competitive inhibitors
What do competitive inhibitors form?
A physical barrier
Competitive inhibitors
What does the physical barrier prevent?
The formation of enzyme-substrate-complexes
Competitive inhibitors
Why are competitive inhibitors competitive?
Because both inhibitor and substrate can fit into the active site they compete with each other for the enzyme
Non-competitive inhibitors
What do non-competitive inhibitors bind to?
A separate part on an enzyme called its albsteric site
Non-competitive inhibitors
What does binding of a non-competitive inhibitor cause?
A conformational change in the enzyme
Non-competitive inhibitors
What does the conformational change alter?
Alters the shape of the enzymes active site so that it is not complementary with its substrate
Non-competitive inhibitors
Why are non-competitive inhibitors non-competitive?
Because these inhibitors don’t bind to the active site they don’t compete with substrates
Which has a more powerful inhibition effect?
Competitive or non-competitive inhibitors
Non-competitive inhibitors
Do competitive inhibitors bind reversibly or permanently?
Reversibly
Do non-competitive inhibitors bind reversibly or permanently?
Permanently
End product inhibition
What do cells usually only want?
Usually cells only want a certain amount of a molecule being produced
End product inhibition
In some cases what does one of the products act as?
In some cases one of the products acts as an inhibitor to another enzyme pathway
End product inhibition
What is end product inhibition?
When the inhibitor is non-competitive and the last product in the pathway it’s called end-product inhibition
End product inhibition
What causes more inhibition to occur?
If the concentration of the final product is high, then more inhibition will occur
End product inhibition
What will greater inhibition lead to?
Greater inhibition will lead to a decrease in the amount of end product being produced
End product inhibition
Why else will inhibition decrease?
Inhibition also decreases if the concentration of end product decreases
End product inhibition
What is end product inhibition an example of?
A negative feedback loop
End product inhibition
What does a negative feedback loop ensure?
ensures the concentration of a product stays roughly consistent
