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A covalent chemical bond that links two carbon atoms through a phosphate group, especially the bonds that link the pentose sugars of adjacent nucleotides in polynucleotide chains of RNA and DNA.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.
phosphodiester bondThe chemical linkages that join up the sugar, base and phosphate NUCLEOTIDES of DNA and RNA into polynucleotide strands. The subunits of the strand are triphosphate nucleosides, but when a number of these join up (polymerize) under the action of the enzyme DNA polymerase, two of the phosphates are cleaved off leaving only one phosphorous atom between each pair of adjacent sugar molecules. The two ester (diester) bonds in each linkage are Carbon-Oxygen-Phosphorus from the 5’-carbon on one sugar and Carbon-Oxygen-Phosphorus from the 3’-carbon on the next. The hydroxyl (-OH) on the 3’-carbon is also lost.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
phosphodiester bonda bond between a sugar group and a phosphate group. In NUCLEIC ACIDS the NUCLEOTIDES are covalently linked by phosphodiester bonds between the phosphate and the 3′ and 5′ hydroxyls of adjacent sugars resulting in an alternating sugar-phosphate backbone:
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005