The salvage cycle interconverts purine bases, nucleosides and nucleotides released as by-products of cellular
metabolism or from the catabolism of nucleic acids or nucleotide cofactors.
This strategy for purine nucleotide synthesis is energetically favorable for a cell since only one salvage reaction requires ATP (phosphorylation of nucleosides to nucleotides).
For example, bases and nucleosides released from storage organs during germination or by senscencing leaves are recycled by this pathway
Operation of the salvage pathway also reduces the levels of purine bases and nucleosides that may otherwise be inhibitory to other metabolic reactions.