ABSTRACT
The basis of a deoxyribonucleic arid (DNA) molecule is a polymer of deoxynucleotides linked together by phosphodiester bonds. These occur by forming phosphoester bonds between de-oxyribose groups of adjacent molecules. In actual fact, deoxytriphosphonucleosides are used to build the polymer rather than monophosphonucleosides as illustrated, and pyrophosphate is cleaved during polymerisation. The typical helix that is associated with DNA forms because the hydrophobic bases are pushed together in the interior of the molecule and the charged phosphate groups, which are very water soluble, are pushed towards the outside. An important feature of DNA laboratory technology is to separate the strands so that copies of the DNA can be made. Nucleases catalyse the hydrolysis of phosphodiester linkages of nucleic acids. Some are required for the synthesis and repair of DNA and others for the production and degradation of ribonucleic add.
