Ribonucleotides are the building blocks of ribonucleic acid (RNA). Each ribonucleotide consists of three components: a ribose sugar, a phosphate group, and a nitrogenous base. The nitrogenous bases can be adenine (A), guanine (G), cytosine (C), or uracil (U). These components link together to form the long chains of RNA, which play crucial roles in various biological processes, including protein synthesis and gene regulation. In addition to their role in RNA, ribonucleotides are also involved in cellular energy transfer. For example, adenosine triphosphate (ATP), a ribonucleotide, serves as the primary energy currency of cells. Ribonucleotides are essential for life, as they participate in critical functions such as cellular signaling and metabolism.