How are nucleotides classified?

Nucleotides are classified based on the type of nitrogenous base they contain, which is fundamental to their role in the structure and function of nucleic acids like DNA and RNA. Each nucleotide consists of three components: a phosphate group, a five-carbon sugar, and a nitrogenous base. The nitrogenous bases can be classified into two categories: purines (adenine and guanine) and pyrimidines (cytosine, thymine, and uracil). This classification based on the nitrogenous base is crucial because it determines how nucleotides pair in the DNA double helix and how they are involved in various biological processes such as protein synthesis and cellular metabolism. The differences in the nitrogenous bases contribute to the genetic code and the specific biochemical pathways in which these nucleotides participate. Understanding this classification helps in grasping the fundamental principles of genetics and molecular biology.