The role of enzymes in biochemical reactions is to act as biological catalysts that speed up reactions without being consumed in the process. Enzymes lower the activation energy required for reactions to proceed, allowing them to occur more readily and efficiently. They are highly specific, often catalyzing only one type of reaction or acting on a specific substrate. Enzymes are crucial for various biological processes, including metabolism, digestion, and DNA replication, making them vital for life and homeostasis.