Book excerpt: Phosphorus Chemistry Directed Towards Biology presents an understanding of reaction mechanisms of organophosphorus compounds. This book discusses the development of analytical tools for the study of the chemistry of phosphorus, which promoted research in nucleic acid chemistry. Organized into 22 chapters, this book begins with an overview of the importance of the bacterial cell wall in maintaining the integrity of the cell in various environments. This text then examines the chemical problems concerning hypermodification and deprotection steps. Other chapters consider the reactive phosphorylating intermediates used in the oligonucleotide chemistry. This book discusses as well the possible role of phosphodiester triazolides and tetrazolides in the phosphotriester formation with arenesulfonyltriazolides and tetrazolides. The final chapter deals with the isolation of proteins involved in the synthesis and recognition of mRNA caps. This book is a valuable resource for phosphorus chemists, biologists, scientists, research workers, teachers, and students.