Enzyme inhibition: competitive and non-competitive

Created by

Max Mottram

Cards (89)

What is the role of the active site in competitive inhibition?
It is blocked by the inhibitor, preventing binding
How does inhibition affect the reaction process?
Inhibitor binds to enzyme, preventing substrate from binding
This blocks the enzyme's catalytic activity, slowing or stopping the reaction
Different types of inhibition (competitive, non-competitive, uncompetitive) have varying effects
What is the name of the process shown in the image?
Reaction and inhibition
What are the key differences between competitive, non-competitive, and uncompetitive inhibition?
Competitive inhibition: Inhibitor binds to active site, preventing substrate binding
Non-competitive inhibition: Inhibitor binds elsewhere, changing enzyme's shape and reducing activity
Uncompetitive inhibition: Inhibitor binds to enzyme-substrate complex, preventing product release
How do the two diagrams illustrate the difference between reaction and inhibition?
The first diagram shows the normal reaction process, while the second diagram shows how an inhibitor can block the reaction
How do the two diagrams illustrate the difference between reaction and inhibition?
The first diagram shows the normal reaction process, while the second diagram shows how an inhibitor can block the reaction
What are the key points of enzyme inhibition?
Blocks an enzyme's activity
Inhibitors are the blocking substances
Can slow or stop reactions
Inhibitors bind to disrupt enzyme function
What is competitive inhibition?
Inhibition by a similar-shaped inhibitor
How does a competitive inhibitor affect the active site of an enzyme?
It competes with the substrate for binding
What is the result of the conformational change in the enzyme during non-competitive inhibition?
The substrate can't bind effectively to the active site
What are substances that stop enzymes called?
Inhibitors
What are the steps involved in non-competitive inhibition?
Inhibitor binds to allosteric site
Active site shape changes
Substrate can't bind effectively
What are the key features of competitive inhibition?
Competes with substrate for active site
Has a similar shape to the substrate
Blocks substrate from binding
Reduces enzyme's activity
What effect does non-competitive inhibition have on the active site?
It causes a conformational change in the active site
How does a competitive inhibitor affect the enzyme kinetics compared to the normal enzyme?
It has the same Vmax but a different Km
Where does a non-competitive inhibitor bind on the enzyme?
To the allosteric site of the enzyme
What is the name of the process shown in the image?
Reaction and inhibition
How does increasing substrate concentration influence enzyme-substrate and enzyme-inhibitor binding?
Increasing substrate favors enzyme-substrate binding
Decreases enzyme-inhibitor binding
Restores enzyme activity
How does a noncompetitive inhibitor affect the enzyme kinetics compared to the normal enzyme?
It has the same Km but a different Vmax
What is the mechanism of competitive inhibition in enzymes?
Inhibitor resembles substrate shape
Binds to enzyme's active site
Forms enzyme-inhibitor complex
Binding is typically reversible
Higher substrate concentration can displace inhibitor
What happens to enzyme activity when substrate concentration is low in competitive inhibition?
Inhibition increases as substrate competes less
What is the effect of competitive inhibition on enzyme activity?
It reduces the enzyme's activity
How does increased substrate concentration affect competitive inhibition?
It reduces inhibition by competing for active site
How does a competitive inhibitor affect the enzyme kinetics compared to the normal enzyme?
It has the same Vmax but a different Km
What are the key differences between competitive and noncompetitive inhibitors based on the enzyme kinetics shown in the image?
Competitive inhibitor: Same Vmax, different Km
Noncompetitive inhibitor: Same Km, different Vmax
What is non-competitive inhibition?
Inhibition when an inhibitor binds to an allosteric site
How does cyanide inhibit enzyme activity?
It binds to an allosteric site, altering the active site
What analogy is used to explain non-competitive inhibition?
Changing the lock on a door
Keys won't fit because the lock is different
What are the key steps in the reaction process shown?
Substrate binds to enzyme, forming enzyme-substrate complex
Enzyme catalyzes reaction, converting substrate to product
Product is released, leaving the enzyme free to catalyze another reaction
What color is the substrate in the provided analogy image?
Yellow
How does the presence of an inhibitor affect the binding of the substrate to the enzyme?
It prevents the substrate from binding to the active site
What color is the inhibitor in the provided analogy image?
Blue
How do non-competitive inhibitors affect substrate competition?
They compete indirectly with the substrate
What is the difference between a competitive inhibitor and a noncompetitive inhibitor?
Competitive inhibitor: Same Vmax as normal enzyme, different Km
Noncompetitive inhibitor: Same Km as normal enzyme, different Vmax
What is the effect of competitive inhibitors on enzyme activity?
It depends on substrate concentration
How do inhibitors affect enzyme reactions?
They can slow down or completely stop reactions.
What is the purpose of the process shown in the image?
To illustrate how a reaction can be inhibited
What are the key steps in the reaction process shown?
Substrate binds to enzyme, forming enzyme-substrate complex
Enzyme catalyzes reaction, converting substrate to product
Product is released, leaving the enzyme free to catalyze another reaction
How does non-competitive inhibition affect the active site?
It alters the shape of the active site
What is the symbol used to represent the substrate concentration in the image?
[S]