An inhibitor, often referred to as a blocker, is a substance that slows down or prevents a specific biological process. In the context of biochemistry, inhibitors can bind to enzymes, preventing them from catalyzing reactions. This can be crucial in regulating metabolic pathways and maintaining homeostasis within living organisms. In pharmaceuticals, inhibitors are commonly used to treat various conditions. For example, ACE inhibitors are used to manage high blood pressure by blocking the action of the enzyme that narrows blood vessels. Similarly, protease inhibitors are vital in treating viral infections, such as HIV, by blocking the enzymes that viruses need to replicate.