The Molecular Carrier Of Genetic Information - 1213 Words

Maia Regman Ms. Sherwood AP Biology 29 January 2015 Question One Because on the work of all of the scientists cited below, DNA can be identified as the molecular carrier of genetic information. By knowing DNA carries genetic information, and not proteins, by knowing DNA’s structure, and knowing DNA is the transforming principle, DNA has become the basis of genetic research and its study has advanced biological and medical science. Alfred Hershey and Martha Chase used experiments involving a T2 bacteriophage to exclude protein as hereditary material. In 1952, Hershey and Chase used the virus, which infects E. coli, to demonstrate that DNA is genetic material. The phage infected the bacterial cell and injected their DNA into the cell.†¦show more content†¦These results are significant because it contributed to the knowledge of DNA function. James Watson wrote that their experiment showed that finding a three-dimensional structure of DNA was the next major objective for biologists. Their discovery contributed to Francis Crick’s finding of the double helix. Oswald Avery discovered with his colleagues in the 1940 s that the transforming principle is DNA, and and therefore a gene is made of DNA. This was proof that DNA, and not protein, is the genetic molecule. Oswald Avery, Colin Macleod, Maclyn McCarty used identical extractions from D cells that are heat-treated. These cells were treated with hydrolytic enzymes that destroyed proteins, RNA or DNA. After these treatments, the extracts were mixed with live R cells. Encapuslated S cells appeared in all the cultures except for the S strain extract that was treated with DNAse-this showed that DNA was responsible for transformation. Proteases and lipases did not inactivate the transforming principle, so the transforming principle was both protein and and lipid-free. Avery and McCarty concluded that the transforming substance was therefore DNA. Watson and Crick’s experiments showed that nucleic acids had the capacity to affect hereditary traits. Watson and Crick furthered the understanding of DNA as the molecular carrier of genetic information by first determining its structure. The scientists analyzed Rosalind