filmov
tv
4 Enzyme Inhibitors
Показать описание
4 types of enzyme inhibitors on the MCAT ⬇️
But first, don’t forget to Like & Save!!
1. Competitive:This type of inhibitor competes with the substrate for binding at the active site.
If the substrate concentration is high enough, the substrate can outcompete the inhibitor, Vmax is not affected
Therefore, the Km of the reaction to which a competitive inhibitor has been added is increased compared to the Km of the uninhibited reaction.
2. Noncompetitive: For this one, instead of competing for the active site, the inhibitor binds to a different site on the enzyme called the allosteric site.
The inhibitor’s binding changes the enzyme’s shape, making the active site less effective at catalyzing the reaction.
The Vmax decreases because the enzyme’s catalytic efficiency gets a little messed up, but the Km remains unchanged since the inhibitor doesn’t directly compete with the substrate.
3. Uncompetitive: In this case, the inhibitor ONLY binds to the enzyme-substrate complex, not the free enzyme before the substrate has bound.
Uncompetitive inhibitors, like non-competitive inhibitors, bind to allosteric sites.
Here the Vmax also decreases, limiting the amount of available enzyme-substrate complex which can be converted to product.
What’s different in uncompetitive is that the Km decreases since the inhibitor actually ENHANCES the affinity of the enzyme for the substrate.
4. Mixed type inhibition: This one combines elements of competitive, noncompetitive, and uncompetitive inhibition. In this case, the inhibitor can bind to either the unoccupied enzyme, or the the enzyme-substrate complex. For mixed-type inhibition, Km varies, but since this type of inhibitor always binds to an allosteric site, additional substrate cannot overcome inhibition, Vmax decreases
But first, don’t forget to Like & Save!!
1. Competitive:This type of inhibitor competes with the substrate for binding at the active site.
If the substrate concentration is high enough, the substrate can outcompete the inhibitor, Vmax is not affected
Therefore, the Km of the reaction to which a competitive inhibitor has been added is increased compared to the Km of the uninhibited reaction.
2. Noncompetitive: For this one, instead of competing for the active site, the inhibitor binds to a different site on the enzyme called the allosteric site.
The inhibitor’s binding changes the enzyme’s shape, making the active site less effective at catalyzing the reaction.
The Vmax decreases because the enzyme’s catalytic efficiency gets a little messed up, but the Km remains unchanged since the inhibitor doesn’t directly compete with the substrate.
3. Uncompetitive: In this case, the inhibitor ONLY binds to the enzyme-substrate complex, not the free enzyme before the substrate has bound.
Uncompetitive inhibitors, like non-competitive inhibitors, bind to allosteric sites.
Here the Vmax also decreases, limiting the amount of available enzyme-substrate complex which can be converted to product.
What’s different in uncompetitive is that the Km decreases since the inhibitor actually ENHANCES the affinity of the enzyme for the substrate.
4. Mixed type inhibition: This one combines elements of competitive, noncompetitive, and uncompetitive inhibition. In this case, the inhibitor can bind to either the unoccupied enzyme, or the the enzyme-substrate complex. For mixed-type inhibition, Km varies, but since this type of inhibitor always binds to an allosteric site, additional substrate cannot overcome inhibition, Vmax decreases