Enzymes play a crucial role in metabolic pathways by acting as catalysts that accelerate biochemical reactions without being consumed. They lower the activation energy required for reactions, allowing metabolic processes to occur efficiently. Each enzyme is specific to a particular substrate, facilitating the transformation of substrates into products. This specificity is vital in regulating metabolism and maintaining homeostasis in organisms. Without enzymes, the rate of metabolic reactions would be too slow to sustain life, emphasizing their importance in energy production, biosynthesis, and overall cellular function.