In studying a particular biomolecule (a protein, nucleic acid, carbohydrate, or lipid) in the laboratory, the biochemist first needs to separate it from other biomolecules in the sample (that is, it needs to be purified). specific purification techniques are described later in the text. however, by looking at the monomeric subunits and functional groups of a biomolecule, you should have some ideas about the characteristics of the molecule that would allow you to separate it from other molecules. look for differences in ionizable groups, polarity, solubility in water, size, and shape. based on the characteristics of each type of molecule, select the way(s) in which amino sugars such as glucosamine could be separated from steroid hormones such as estradiol