Pentose sugar is a component of nucleotides. Nucleotides are biological molecules that act as monomers and as subunits of DNA and RNA. These biological molecules carry energy packets to the cell in the form of nucleoside triphosphate (ATP, GTP, CTP, and UTP), which play a key role in metabolic processes.

Nucleotides are formed by combining a nitrogenous base and a phosphate group with pentose sugar. The main polymer of nucleotides is a nucleic acid. This sugar is found only after the hydrolysis of nucleic acids.