Читать книгу Principles of Microbial Diversity - James W. Brown - Страница 23

All cells encode information in the form of DNA. The DNA in all cells is composed of the same four bases (G, A, T, and C) and the same sugar (2′-deoxy-D-ribose), assembled with the same chemical structure and stereochemistry. Information in DNA is stored by using a universal three-letter code (e.g., AAA encodes lysine in all cells), and the DNA replication process is handled the same in all organisms (the replication fork complexes are all very much alike). The function of DNA is carried out via transcription into RNA, using RNA polymerases that are all essentially alike.