Summary Of Rosalind Franklin: The Dark Lady Of DNA
618 Words3 Pages
Amy Lu
AP Biology
12 December 2015
Biology Extra Credit
Rosalind Franklin: The Dark Lady of DNA
Part I: DNA, deoxyribonucleic acid, was a topic of interest in scientific study in the 1900s. DNA is what makes up for the complex genotypic and phenotypic differences in everyone. DNA is located in the nucleus of cells, and it has a complex structure. DNA is double stranded and double helical in structure. The two strands of DNA are made up of a sugar-phosphate backbone which is negative in charge. The two strands run antiparallel to each other with 5’ ends and 3’ ends, and they are connected by paired nitrogenous bases. In DNA, the four nitrogenous bases are Adenine, Thymine, Guanine, and Cytosine. Adenine and Thymine pair together with hydrogen bonds, and Guanine and Cytosine pair together with hydrogen bonds as well. Thymine and Cytosine are one-ringed pyrimidines, and Adenine and Guanine are two-ringed purines.…show more content… These were produced using x-rays to bombard a molecule to see the structure of the molecule, a technique Franklin mastered in a Parisian laboratory. With this technique, she took a photograph of DNA in May of the year 1952 that helped Rosalind discover the double helical structure of DNA when she interpreted and understood the crystalline molecules’ x-rays. Her x-ray crystallography proved her finding that DNA’s structure is double helical, which was clearly depicted in the image. This was a profound piece of new information that significantly helped Watson and Crick’s building of the DNA