Animal Biotechnology

DNA STRUCTURE

• Double helix model requires the two polynucleotide chains to run in opposite directions (antiparallel). Therefore one strand runs in the 5’---- 3’ direction while the other strand runs in 3’------- 5’. The two polynucleotide strands are joined only by hydrogen bonds.
• Four different structural forms are present. They are A form, B form, and Z form. The B form was constructed by Watson and Crick and naturally present.