Phosphodiester bond - wikipedia Phosphodiester bond Diagram of phosphodiester bonds ( PO ) between three nucleotides. A phosphodiester bond occurs when exactly two of the hydroxyl groups in phosphoric acid react with hydroxyl groups on other molecules to form two ester bonds. Phosphodiester bonds are central to all life on Earth, as they make up the backbone of the strands of nucleic acid. In DNA and RNA, the phosphodiester bond is the linkage between the 3 ' carbon atom of one sugar molecule and the 5 ' carbon atom of another, deoxyribose in DNA and ribose in RNA. Strong covalent bonds form between the phosphate group and two 5 - carbon ring carbohydrates ( pentoses ) over two ester bonds. The phosphate groups in the phosphodiester bond are negatively charged. Because the phosphate groups have a pK near 0, they are negatively charged at pH 7. This repulsion forces the phosphates to take opposite sides of the DNA strands and is neutralized by proteins ( histones ), metal ions such as magnesium, and polyamines. In order for the phosphodiester bond to be formed and the nucleotides to be joined, the tri-phosphate or di - phosphate forms of the nucleotide building blocks are broken apart to give off energy required to drive the enzyme - catalyzed reaction. When a single phosphate or two phosphates known as pyrophosphates break away and catalyze the reaction, the phosphodiester bond is formed. Hydrolysis of phosphodiester bonds can be catalyzed by the action of phosphodiesterases which play an important role in repairing DNA sequences. The phosphodiester linkage between two ribonucleotides can be broken by alkaline hydrolysis, whereas the linkage between two deoxyribonucleotides is more stable under these conditions. The relative ease of RNA hydrolysis is an effect of the presence of the 2 ' hydroxyl group. Contents 1 Enzyme activity 2 See also 3 Notes 4 References Enzyme activity A phosphodiesterase is an enzyme that catalyzes the hydrolysis of phosphodiester bonds, for instance a bond in a molecule of cyclic AMP or cyclic GMP. An enzyme that plays an important role in the repair of oxidative DNA damage is the 3 ' - phosphodiesterase. During the replication of DNA, there is a hole between the phosphates in the backbone left by DNA polymerase I. DNA ligase is able to form a phosphodiester bond between the nucleotides. See also Phosphodiesterase Phosphodiesterase inhibitor DNA replication, DNA, ATP Teichoic acid, DNase I PDE5 Nick ( DNA ) Notes Jump up ^ Even prions, the only reproducers without nucleic acid and generally considered beyond the boundary of life, require RNA - containing life to reproduce themselves. References Jump up ^ `` Phosphodiester bond ''. School of BioMedical Sciences Wiki. Retrieved from `` https://en.wikipedia.org/w/index.php?title=Phosphodiester_bond&oldid=793566978 '' Categories : Organophosphates Molecular biology Biology and pharmacology of chemical elements Hidden categories : All articles with unsourced statements Articles with unsourced statements from February 2014 Articles with unsourced statements from August 2009 Talk Contents About Wikipedia Bosanski Català Čeština Dansk Deutsch Español فارسی Français Galego 한국어 Hrvatski Italiano עברית ქართული Македонски Nederlands 日本 語 Polski Português Русский Српски / srpski Srpskohrvatski / српскохрватски Suomi Türkçe Українська اردو 中文 Edit links This page was last edited on 2 August 2017, at 15 : 26. Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: where are the phosphodiester bonds located in the double helix of dna
Answer: between the 3' carbon atom of one sugar molecule and the 5' carbon atom of another, deoxyribose