Enzyme inhibition happens when a molecule attaches to an enzyme and changes how it works. There are two main types of enzyme inhibition: competitive and non-competitive. Here’s a simple breakdown of the differences:

Competitive Inhibition

• Where It Binds: The inhibitor competes with the molecule (called a substrate) that the enzyme usually works on.
• Effect on KM: It makes the Michaelis constant ($K_M$) go up, but it doesn’t change the maximum speed ($V_{max}$) of the reaction.
• Example: Statins are a type of drug that compete with HMG-CoA to block the enzyme that helps make cholesterol.

Non-Competitive Inhibition

• Where It Binds: The inhibitor sticks to a different part of the enzyme, called the allosteric site, instead of the active site.
• Effect on Vmax: It reduces the maximum speed ($V_{max}$) of the reaction, but the Michaelis constant ($K_M$) stays the same.
• Example: Heavy metals can stop enzymes from working by sticking to places other than the active site.

Knowing the differences between these two types of inhibition is really important. It helps scientists design better drugs and find new ways to treat illnesses.