Final answer:
A nucleotide, the building block of DNA and RNA, consists of a nitrogenous base, a pentose sugar, and a phosphate group. These compounds are crucial for the formation of the genetic material's structure.
Step-by-step explanation:
The three components of a nucleotide are a nitrogenous base, a pentose sugar, and a phosphate group. Nucleotides are the building blocks of nucleic acids like DNA and RNA. In DNA, the pentose sugar is deoxyribose, which lacks an oxygen atom at the 2' position compared to ribose, the sugar found in RNA. Additionally, the nitrogenous bases are either purines (adenine and guanine) or pyrimidines (cytosine, thymine, and uracil).
The nitrogenous base attaches to the 1' position of the pentose sugar, and the phosphate group is typically connected to the 5' position of the same sugar. The attachment of the phosphate group of one nucleotide to the 3' hydroxyl group of another forms the backbone of the polynucleotide chain.