True about DNA structure

Deoxyribonucleic acid (DNA) stores information for the synthesis of specific proteins. DNA has deoxyribose as its sugar. DNA consists of a phosphate group, a sugar, and a nitrogenous base. The structure of DNA is a helical, double-stranded macromolecule with bases projecting into the interior of the molecule. These two strands are always complementary in sequence. One strand serves as a template for the formation of the other during DNA replication, a major source of inheritance. This unique feature of DNA provides a mechanism for the continuity of life. The structure of DNA was found by Rosalind Franklin when she used x-ray crystallography to study the genetic material. The x-ray photo she obtained revealed the physical structure of DNA as a helix. DNA has a double helix structure. The outer edges are formed by alternating deoxyribose sugar molecules and phosphate groups, which make up the sugar-phosphate backbone. The two strands run in opposite directions, one going in a 3' to 5' direction and the other going in a 5' to 3' direction. The nitrogenous bases are positioned inside the helix structure like "rungs on a ladder," due to the hydrophobic effect, and stabilized by hydrogen bonding.