Cell Genetics

Remember that the two major types of molecules required for life are proteins and nucleic acids; the former, namely those bearing catalytic activity, constitute the tools that bring about the reactions of life (i.e., metabolism), in an efficient and controlled fashion—whereas the latter contain the instructions to manufacture such proteins, as well as auxiliary structures thereto, so that its offspring will be able to perform similar metabolic functions. Therefore, the protein makeup of a cell defines its metabolic processes—meaning that the types of enzymes present and their concentrations set the underlying reaction network; however, proteins play other roles, namely regulation (e.g., interferon, insulin), transport (e.g., lactose permease, hemoglobin), protection (e.g., thrombin, antibodies), defense (e.g., snake venom, Bacillus thuringiensis toxin), storage (e.g., ovalbumin, casein), motility (e.g., dynein, myosin/actin), and support (e.g., collagen, elastin). The structures of the various forms of nucleic acids are schematically depicted in Fig. 3.1; the study of how such information is transmitted is termed genetics.