What is the minimum molecular mass for a substance to be classified as a macromolecule?

A substance is classified as a macromolecule if it has a high molecular mass, typically in the range of thousands of daltons, reflecting its extensive molecular structure and complexity. The threshold for defining a macromolecule is generally accepted to be around 5,000 g/mol or higher. This is because macromolecules, such as proteins, nucleic acids, and polysaccharides, often comprise large numbers of smaller molecular units (like amino acids, nucleotides, or monosaccharides) linked together, resulting in substantial molecular weights.

Substances with a molecular mass below this threshold, such as those around 1,000 g/mol or even less, are usually considered small molecules and do not exhibit the characteristics associated with macromolecules, such as high molecular weight, complexity in shape, and diversity in functional groups. Within this context, 5,000 g/mol represents an effective cutoff that aligns with the structural and functional diversity typical of macromolecular compounds.