What type of chemical compounds are purines?

Purines are a class of chemical compounds that serve as essential building blocks of nucleotides, which are the fundamental units of nucleic acids like DNA and RNA. Nucleotides themselves consist of three components: a nitrogenous base, a sugar, and a phosphate group. Purines, specifically adenine and guanine, are one of the two types of nitrogenous bases found in nucleotides, with the other type being pyrimidines.

Understanding the role of purines in nucleotides is crucial because these nucleotides are vital for a variety of biological functions, including the storage and transfer of genetic information and energy transfer in cells (through molecules like ATP). Therefore, identifying purines as building blocks of nucleotides highlights their core function in genetic material and cellular metabolism.

The other choices relate to different types of biological macromolecules. Building blocks of proteins refer to amino acids, components of fats pertain to fatty acids and glycerol, while disaccharides are formed from the linkage of monosaccharides. None of these categories apply to purines, emphasizing their unique role in the structure of nucleotides specifically.