Question

explain the structure of dna

Answer 1

DNA is made up of six smaller molecules -- a five carbon sugar called deoxyribose, a phosphate molecule and four different nitrogenous bases (adenine, thymine, cytosine and guanine). Using research from many sources, including chemically accurate models, Watson and Crick discovered how these six subunits were arranged to make the the structure of DNA. The model is called a double helix because two long strands twist around each other like a twisted ladder. The rails of the ladder are made of alternating sugar and phosphate molecules. The steps of the ladder are made of two bases joined together with either two or three weak hydrogen bonds.

Answer 2

 It contains the genetic instructions needed for functioning of organisms.  It is a double helix with two polymer molecules forming strands with each other.  These helical strands are called the backbone.  The back bone contains deoxyribose sugars with 5 carbons.  The carbons are attached to phosphates on one side and to bases in between the two strands. The bases are Adenine , Thymine, Cytosine, Guanine.  Two bases form hydrogen bonds between them and join the two strands of the double helix.