| [ Summary ] |
Phosphorus in the form of phosphates plays important roles in cellular activity. Strong negative charges and hydrophilicity provide 1) stability and a high degree of freedom for connection of nucleosides in the form of nucleic acid, 2) Smooth extensibility and undisturbed continuity to cell membranes in the form of phospholipids, 3) a convenient vehicle for free energy in the form of adenosine tri-phosphates, and 4) prominent tags for control of activity of functional proteins under the effects of kinase and phosphorylase. The roles played by ATP in muscle cells, which are highly specialized to perform contractile tasks, suggest a general strategy of living organisms on the earth to realize life utilizing phosphorylation processes. |