The building blocks of nucleic acids are nucleotides. Each nucleotide is composed of three essential components:

• A pentose sugar : This is a five-carbon sugar. In DNA, the sugar is deoxyribose, which lacks an oxygen atom at the 2' position. In RNA, the sugar is ribose, which has a hydroxyl group at the 2' position.
• A phosphate group : This group links the sugars of adjacent nucleotides via phosphodiester bonds, forming the sugar-phosphate backbone of the nucleic acid.
• A nitrogenous base : This base is attached to the sugar and can be one of several types. In DNA, the bases are adenine (A), cytosine (C), guanine (G), and thymine (T). In RNA, uracil (U) replaces thymine (T) while adenine, cytosine, and guanine remain the same.

These nucleotides polymerize to form the long chains of DNA and RNA, encoding genetic information and playing critical roles in cellular function