The DNA Structure

So our main topic for this class was DNA. We talked about the double helix DNA structure and even created a paper model of it. The double helix structure was discovered by James D. Watson and Francis Crick. A man, Erwin Chargaff, found that a a composition of DNA varied one species to another, but all organisms had the same bases. These bases are Adenine (A), Cytosine (C), Thymine (T), and Guanine (G). Adenine is equal to Thymine and Cytosine is equal to Guanine. Hydrogen bonds are what hold together the Adenines with the Thymines and the Cytosines with the Guanines. Thymine and Cytosine are Pyrimidines. Adenine and Guanine are Purines. The bonds between the sugar and phosphate in the strucutre are called phosphodiester bonds. We began making a DNA model today and will begin the replication of it next class.