DNA strand is made from alternating phospate and sugar residues. Thesre two strands run in opposite directions to each other and therfore antiparallel Attached to each sugar is one of four types of molecules called bases. The sugar in DNA is 2 - deoxyribose which is apentose sugar searches of DNA into the related nuclear acid RNA in aproesss sugsrs are joinrd to phospate groups that from phosphodiester bonds btwn the third and4th carbon atoms adjacent sugar rings.

DNA is a long polymer made from repeating units called nucleotides. The DNA is chain is 20 - 26 angstroms wide. DNA polymers can be very large moleculars containing millions of nucleotides chemically with backbones made of sugars and phospates groups joined by ester bonds these onformation is using the genetic code. Phospate groups are joined by ester bonds. In living organisms.

DNA does not usually exist as a single molecule but it exists as a pair of molecules that are held tightly together. These two long strands and entwine like vines in the shape a double helix. which holds chain together and a base which interacts with the other DNA strand in the helix. A base linked to a sugar is nucleiotide. If muultiple nucleiotide are linked to together as in DNA this polymer is known as a polynucleiotide