ABSTRACT
This chapter will discuss the fundamental classes of biological macromolecules (biopolymers). We will first explore nucleic acids (DNA and RNA), proteins, and complex carbohydrates (polysaccharides and oligosaccharides). These biopolymers are built from their respective molecular building blocks: nucleotides, amino acids, and monosaccharides. In addition, we will also examine membranes, which, while not biopolymers, are essential biomolecular structures formed through the self-assembly of lipid units via noncovalent interactions. All these macrostructures represent a unifying principle of life, as each class serves the same functions across all domains of life. Moreover, the conservation of biosynthetic pathways for nucleic acids, proteins, and complex carbohydrates among bacteria, archaea, and eukaryotes suggests that these routes emerged already in the early ancestral life forms and were inherited by all subsequent lineages rather than evolved independently.
