Enzymes are vital biological catalysts that accelerate chemical reactions in living organisms. They lower the activation energy required for reactions, allowing cellular processes to occur at physiological temperatures. Enzymes are highly specific, meaning they typically catalyze only one type of reaction or act on a specific substrate. They play a crucial role in various biological processes, including digestion, metabolism, and DNA replication. Without enzymes, many reactions would proceed too slowly to sustain life, demonstrating their essential function in maintaining homeostasis and overall biological activity.