In Section 22.6, three important classes of biologically important natural polymers are discussed. What are the three classes, what are the monomers used to form the polymers, and why are they biologically important?

Carbohydrates are a class of biologically important polymers consisting of monomer units called monosaccharides. Monosaccharides are simple sugars such as glucose, fructose, and galactose. These polymers can be classified as disaccharides, oligosaccharides, or polysaccharides. Carbohydrates play crucial roles in living organisms: they serve as an essential source of energy, contribute to the structural components of cells, and function as cell-to-cell signaling molecules.

Proteins are another class of biologically important polymers. These natural polymers are comprised of monomer units called amino acids. There are 20 standard amino acids that can combine to form a vast array of proteins structures via peptide bonds. Proteins play a critical role in every biological process, including catalyzing biochemical reactions, providing structural support, facilitating transport of molecules across cell membranes, and coordinating various processes within the body through signaling and regulation.

Nucleic acids are the third class of biologically important natural polymers. Nucleic acids are made up of monomer units called nucleotides, which consist of a nitrogenous base, a five-carbon sugar (either ribose or deoxyribose), and a phosphate group. There are two types of nucleic acids: DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). DNA stores genetic information and serves as the blueprint for synthesizing proteins, while RNA is involved in various cellular processes, including the synthesis of proteins from DNA. Nucleic acids are essential for the storage and transmission of genetic information, protein synthesis, and regulation of gene expression. In conclusion, carbohydrates, proteins, and nucleic acids are the three classes of biologically important natural polymers. Carbohydrates serve as energy sources and structural components, proteins participate in a wide range of cellular processes and functions, and nucleic acids store and transmit genetic information and direct protein synthesis.