BIOL 1020 Lecture Notes - Lecture 20: Ribose, Valine, Ribosomal Rna
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BIOL 1020 Full Course Notes
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First experiment (griffith"s transforming factor= dna: they started this experiment in 1928 but it wasn"t until 1944 they got there answer. Second experiment (hershey and chase experiment: used bacteriophages (viruses that infect bacteria). They made some radioactive with sulfur (proteins) and some were radioactive with phosphorus (dna). They found that what was left was dna and that the proteins made up the capsid which was expelled after infection. The protein does not infect bacterial cells but dna does. Dna was discovered in 1869 by miescher (he extracted dna from the nucleus of pus cells (white blood cells)). Miescher hypothesized that the molecule he had abstracted was the hereditary material but he had no proof. Dna molecule: it consists of a deoxyribose (five carbon sugar); four different nitrogenous bases (adenine (a), guanine (g), cytosine (c), and thymine (t)). Adenine and guanine= purines; cytosine and thymine= pyrimidines); and.
