At a pH of 7.4, most of the phosphorus in the body exists in which form?

At a pH of 7.4, the predominant form of phosphorus in the body is found in bones. The primary component of bones and teeth is hydroxyapatite, which is a mineral form of calcium phosphate. This complex is essential for providing structural integrity and strength to the skeletal system.

Additionally, while phosphorus is involved in various biological molecules, its most abundant storage form in the body relates to the skeletal system. Although ATP and ADP are important phosphorylated compounds that play critical roles in energy metabolism, they are found in much smaller quantities relative to the total phosphorus content in the body. Similarly, while DNA and RNA contain phosphorus, they account for a limited proportion compared to the substantial phosphorus reserves in bone. 2,3-DPG also contains phosphorus but is not a major storage form.

This highlights the essential role of bone not only in providing a physical structure but also in serving as a significant reservoir for phosphorus in the body, particularly at physiological pH levels.