Explain how the structure of DNA is related to its functions. (6 marks)

DNA is double stranded. This enables semi-conservative replication to take place. Each individual strand will act as a template resulting in the formation of an identical DNA molecule.(1) It exists as an a-helix which makes it very compact. (2) It is a very large molecule so it can store a lot of information. (3) The sugar-phosphate backbone provides stability by protecting the internal bases. (4) Between each complementary pair of bases there are weak hydrogen bonds. These can easily be broken down, enabling replication to occur. (5) The specific base sequence enables the storage of information. Proteins are synthesised following the transcription and translation of this sequence. (6)