Is the Phosphate group found in nucleotide of nucleic acids derived from H3PO4? What is the source of PO4 group of a nucleotide found in nucleic acids?
You are right, the phosphate group comes from inorganic phosphate. During glucose metabolism, glucose -6- phosphate is formed due to phosphate donated by ATP. Glucose-6-phosphate can be converted into ribulose-5-phosphate during certain reactions. Finally, ribulose-5-phosphate is converted to ribose-5-phosphate, used in nucleotide metabolism. As phosphate group of ATP, donated to glucose, comes from inorganic phosphate, it is possible to conclude that phosphate of nucleotide has the same origin.