Question

Question:Nucleic acids are diesters of phosphoric acid. Esters are not usually acidic. Why are nucleic acids acidic, or is this name inappropriate?

Short answer

The nucleic acid has an acidic${\text{pK}}_{\text{a}}$value because of phosphoric acid.

Step-by-step solution

Nucleic acid.

The acidity for nucleic acid comes from phosphate groups. They are used to form deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). The replacement of two protons from the phosphoric acid compound with protons from the sugar component of the nucleotide. So leaves only one proton and which is highly acidic. That’s why nucleic acid is acidic.

Nucleic acids are acidic.

The nucleic acids are di-esters of the phosphoric acid compound, but the esters are usually not acidic. An ionizable phosphate group is the backbone of nucleic acids. So, it has an acidic${\text{pK}}_{\text{a}}$value.

Hence, this is the basis of acid in nucleic acid. So it is named nucleic acid.