Which of the following is not a characteristic of macromolecules?

Macromolecules are typically defined by their large size, which stands in contrast to the assertion that they are small. They are complex structures formed by the linkage of smaller units called monomers. This assembly into larger molecules contributes to their significant molecular weight, distinguishing them from smaller molecules and enabling their varied functions in biological systems.

Furthermore, macromolecules play crucial roles in biological functions, including serving as structural components, enzymes, and energy storage components. Such functions underscore their importance in the life processes of organisms. The choice indicating that macromolecules are small does not align with the fundamental characteristics that define these biological entities. In summary, the statement regarding their small size is inconsistent with the established understanding of macromolecules, thus making it the correct choice for this question.