Title: Nucleic Acids Introduction: Most biologists were now convinced that DNA was the genetic material. However, they still did not know what specific arrangements gave DNA its unique properties. How is it capable of storing, copying and transferring information onto succeeding generations. How does its structure account for its role in heredity? 1- The building blocks of DNA a- The heritable genetic information of an organism is stored in a molecule called DNA (deoxyribonucleic acid) b- c- RNA (ribonucleic acid) also plays a role in the functioning of cells d1- Only four types of nucleic acids make up DNA, each contain abc1- The 4 base pairs are adenine, thymine, quinine and cytosine 2- d-The DNA Strands 1- 2- This repeating set of units is called the sugar-phosphate backbone 3- 4- e- DNA Structure 1- In the early 1950’s Rosalind Franklin and Maurice Wilkens using X-ray crystallography provided a collection of photographs of DNA. These pictures gave clues to the shape and dimensions of complex molecules. These photos showed the basic shape of DNA to be a helix. 2- The Double Helix a- Watson and Crick b- 3- Complimentary base pairing a- Based on the double helix model, Watson and Crick concluded that the base pairs had to align in very specific ways bc- d- In 1953 Watson and Crick published their work in the journal Nature Few milestones in the history of biology have been as important as the discovery of the double helix structure of DNA and complimentary base pairing. With the help of the famous “Photo 51” Watson, Crick and Wilkens received the Nobel prize for their work for Medicine in 1962.