Abstract
Inorganic phosphate (Pi) plays a crucial role in many biochemical pathways. Broad Pi involvement in the structure and function of biological entities reflects a striking unity of inorganic and organic matter in life processes. Pi functions as a constituent of cellular metabolites as well as a building material for bones in vertebrates and shells in some marine species, owing to the ability of Pi to form robust minerals. Dysregulation of phosphate metabolism causes serious medical disorders, such as osteoporosis, arterial medial calcification, hypophosphatemia, and kidney stone formation. The purpose of this chapter is to provide a brief but comprehensive overview of inorganic phosphate biology. The chapter aims at a broad audience that includes advanced graduate students and first-year medical students as well as researchers and scientists interested in the basics of Pi bioorganic, biophysical, bioinorganic, and biomedical chemistry. Herein, the author i) describe major Pi functions in current life forms; ii) highlight unique Pi properties that underpin its role in life processes, iii) rationalize the natural choice of Pi for design of biological molecules, and iv) discuss the possible involvement of inorganic phosphate and its minerals in events that led to the emergence of life.