Here's why:

* Macromolecules are large, complex molecules made up of many smaller subunits called monomers. They are essential for life and play vital roles in various biological processes. Common examples include carbohydrates, lipids (fats), proteins, and nucleic acids (DNA and RNA).

* Micromolecules are small molecules, typically with low molecular weight. They are the building blocks of macromolecules. Examples include sugars, amino acids, and nucleotides.

So, while both macromolecules and micromolecules contain carbon atoms, the key difference lies in their size and complexity.