What role do enzymes play as proteins?

Enzymes are specialized proteins that play a crucial role as catalysts in biochemical reactions. By lowering the activation energy required for chemical reactions to occur, enzymes significantly increase the rate at which these reactions proceed. This catalytic activity is essential for numerous metabolic processes, allowing cells to efficiently carry out the complex reactions necessary for life.

In contrast to the other roles listed, enzymes are not primarily involved in energy storage, structural support, or molecular transport. While cells indeed have proteins that handle those functions—like storage proteins, structural proteins such as collagen, and transport proteins like hemoglobin—enzymes specifically enhance the speed and efficiency of biochemical reactions, making them vital for cellular function and overall metabolism. Their specificity and regulation are also key features that distinguish enzymes from other types of proteins.