# Sugar phosphates > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Sugar_phosphates > Markdown URL: https://mediated.wiki/source/Sugar_phosphates.md > Source: https://en.wikipedia.org/wiki/Sugar_phosphates > Source revision: 1331594318 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) **Sugar phosphates** ([sugars](/source/Sugars) that have added or substituted [phosphate](/source/Phosphate) groups) are often used in biological systems to store or transfer [energy](/source/Energy). They also form the backbone for [DNA](/source/DNA) and [RNA](/source/RNA). Sugar phosphate backbone geometry is altered in the vicinity of the modified nucleotides. Examples include: - [Dihydroxyacetone phosphate](/source/Dihydroxyacetonephosphate) - [Glucose-6-phosphate](/source/Glucose-6-phosphate) - [Phytic acid](/source/Phytic_acid) - [Teichoic acid](/source/Teichoic_acid) ## Electronic structure of the sugar-phosphate backbone The sugar-phosphate backbone has [multiplex](https://en.wiktionary.org/wiki/multiplex) electronic structure and the electron [delocalisation](/source/Delocalisation) complicates its [theoretical](/source/Theoretical) description. Some part of the electronic density is delocalised over the whole backbone and the extent of the delocalisation is affected by backbone conformation due to [hyper-conjugation](/source/Hyper-conjugation) effects. Hyper-conjugation arises from donor-acceptor interactions of localised orbitals in 1,3 positions. ## Phosphodiesters in DNA and RNA The [phosphodiester backbone](/source/Phosphodiester_backbone) of DNA and RNA consists of pairs of [deoxyribose](/source/Deoxyribose) or [ribose](/source/Ribose) sugars linked by phosphates at the respective 3' and 5' positions. The backbone is negatively charged and [hydrophilic](/source/Hydrophilic), which allows strong interactions with water.[1] Sugar-phosphate backbone forms the structural framework of [nucleic acids](/source/Nucleic_acids), including [DNA](/source/DNA) and [RNA](/source/RNA).[2] Sugar phosphates are defined as carbohydrates to which a phosphate group is bound by an ester or an either linkage, depending on whether it involves an alcoholic or a hemiacetalic hydroxyl, respectively. [Solubility](/source/Solubility), acid [hydrolysis](/source/Hydrolysis) rates, acid strengths, and ability to act as sugar group donors are the knowledge of physical and chemical properties required for the analysis of both types of sugar phosphates. The [photosynthetic](/source/Photosynthetic) carbon reduction cycle is closely associated with sugar phosphates, and sugar phosphates are one of the key molecules in metabolism, oxidative pentose phosphate pathways, [gluconeogenesis](/source/Gluconeogenesis), important intermediates in [glycolysis](/source/Glycolysis). Sugar phosphates are not only involved in metabolic regulation and signaling but also involved in the synthesis of other phosphate compounds.[3] ## Peptide nucleic acids Peptide nucleic acid (PNA) is a nucleic acid in which natural nucleic acid has been replaced by a [synthetic peptide](/source/Synthetic_peptide) backbone formed from *N*-(2-amino-ethyl)-glycine units along with sugar phosphate backbone forming in an [achiral](/source/Achiral) and uncharged moiety that mimics RNA or DNA [oligonucleotides](/source/Oligonucleotide). PNA cannot be degraded inside living cells but it is chemically stable and resistant to [hydrolytic](/source/Hydrolytic) (enzymatic) [cleavage](/source/Bond_cleavage).[4] ## Role in metabolism Sugar phosphates are major players in [metabolism](/source/Metabolism) due to their task of storing and transferring energy. Not only ribose 5-phosphate but also fructose 6-phosphate are an intermediate of the pentose-phosphate pathway which generates [nicotinamide adenine dinucleotide phosphate](/source/Nicotinamide_adenine_dinucleotide_phosphate) (NADPH) and pentoses from glucose polymers and their [degradation](/source/Degradation_(chemistry)) products. The pathway is known as [glycolysis](/source/Glycolysis) where the same carbohydrates are degraded into [pyruvates](/source/Pyruvates) thus providing energy. [5] Enzymes are catalysed for the reactions of these pathways. Some [enzymes](/source/Enzymes) contain metal centers in their [active site](/source/Active_site) which is important part of the enzymes and as well as for the catalysed reaction. The phosphate group can coordinate to the metal center for example, 1,6-bisphosphatase and ADP-ribose pyrophosphatase. Phosphoglycerate and several sugar phosphates that are known intermediates of the Calvin photosynthetic [carbon cycle](/source/Carbon_cycle), stimulate light-dependent carbon dioxide fixation by isolated chloroplasts. This ability is shared by certain other metabolites (e.g. glucose 1-phosphate) from which the accepted Calvin-cycle intermediates could easily be derived by known metabolic routes. ## References 1. ["Sugar-phosphate backbone"](https://www.biology-online.org/dictionary/Sugar-phosphate_backbone). 12 September 2020. 1. ["Phosphate Backbone"](https://www.nature.com/scitable/definition/phosphate-backbone-273) 1. "Case Study: Sugar Phosphates - Methods for Analysis of Carbohydrate Metabolism in Photosynthetic Organisms - Chapter 14". [doi:10.1016/B978-0-12-803396-8.00014-4](https://doi.org/10.1016/B978-0-12-803396-8.00014-4) 1. Baerlocher, Gabriela M. & Lansdorp, Peter M. (2004). "Telomere Length Measurements Using Fluorescence In Situ Hybridization and Flow Cytometry". *Cytometry, 4th Edition: New Developments*. Vol. 75. Methods in Cell Biology. pp. 719–750. [doi:10.1016/S0091-679X(04)75031-1](https://doi.org/10.1016/S0091-679X(04)75031-1). ISBN 9780125641708. [PMID 15603450](https://pubmed.ncbi.nlm.nih.gov/15603450) 1. ["Coordination Chemistry of Sugar-Phosphate complexes"](https://edoc.ub.uni-muenchen.de/16190/1/Steinborn_Martin.pdf). Retrieved 2018-02-07. --- Adapted from the Wikipedia article [Sugar phosphates](https://en.wikipedia.org/wiki/Sugar_phosphates) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Sugar_phosphates?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.