What is the primary function of enzymes in biological systems?

Enzymes play a crucial role in biological systems primarily as catalysts that facilitate biochemical reactions. This means that they accelerate reactions by lowering the activation energy needed for those reactions to occur, allowing them to happen more efficiently and under milder conditions than would be possible otherwise. As catalysts, enzymes are not consumed in the reactions they catalyze, which means they can be used repeatedly. This property is vital in sustaining the numerous metabolic processes that occur within living organisms.

The other options, while important functions in biological systems, do not accurately describe the primary role of enzymes. Providing structural support is a function associated with proteins such as collagen or keratin. Carrying oxygen in the blood is specific to hemoglobin, a protein that performs this task. Storing genetic information is the function of DNA, which holds the instructions for the development and functioning of living organisms. Therefore, the choice identifying enzymes as catalysts for biochemical reactions is the most accurate representation of their primary function.