Larger biological molecules are made up of smaller subunits. what are these smaller subunits called

Monomers are small subunits that compose larger molecules or macromolecules. Biomolecules are large molecules present in living organisms. There are four major classes of biomolecules: carbohydrates, lipids, proteins and nucleic acids. Each with monomers: monosaccharides, glycerol and fatty acids, amino acids and nucleotides, respectively.