Purine nucleotides are essential building blocks of nucleic acids, which include DNA and RNA. They consist of a purine base, such as adenine or guanine, attached to a sugar molecule (ribose in RNA and deoxyribose in DNA) and one or more phosphate groups. These nucleotides play a crucial role in cellular processes, including energy transfer and signaling. In addition to their structural role in nucleic acids, purine nucleotides are involved in various metabolic pathways. For example, ATP (adenosine triphosphate) is a key purine nucleotide that serves as the primary energy currency of the cell. Other purine nucleotides, like GTP (guanosine triphosphate), are important for protein synthesis and signal transduction.