" Competitive Inhibition: When there's another molecule that isn't a substrate, yet can bind to the active site of an enzyme. – Penicillin, for example, blocks an enzyme used by bacteria to make cell walls. – Antabuse (disulfiram) is a commercial drug that treats alcoholism by inhibiting the enzyme that breaks down alcohol, leading to severe hangover and illness within 5-10 minutes after drinking. Competitive inhibition can be overcome by increasing substrate concentration. – In other words, substrates can out- compete inhibitors. Analogy: Competitive inhibition is like someone sitting in your seat. "