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Discovery of nucleic acids
Nucleic acids were discovered in 1868, when twenty-four-year-old Swiss physician Friedrich Miescher isolated a new compound from the nuclei of white blood cells. This compound was neither a protein nor lipid nor a carbohydrate; therefore, it was a novel type of biological molecule. -
Levene's Tetranucleotide
-Levene proposed that there were four nucleotides per molecule
-DNA could not strore the genetic code because it was chemically far too simple -
bacterial transformation
What is Bacterial Transformation? Bacterial transformation is a process of horizontal gene transfer by which some bacteria take up foreign genetic material (naked DNA) from the environment. It was first reported in Streptococcus pneumoniae by Griffith in 1928 -
Avery, Macleod & McCarty
Avery, MacLeod, and McCarty demonstrated that DNA from a virulent smooth strain of pneumococcus could transform a rough strain into the smooth variety. This is the first experiment to conclude that DNA is the genetic material. -
Counting Nucleobases
Bacteriophages, also known as phages, are viruses that infect and replicate only in bacterial cells. They are ubiquitous in the environment and are recognized as the most abundant biological agent on earth.The bacteriophage (phage) is a virus that infects bacteria -
Hershey and Chase experiments
Hershey and Chase were able to separate the phages into radioactive sulfur-containing protein ghosts and radioactive phosphorus-containing DNA. They found that the radioactive sulfur protein ghosts could attach to bacterial membranes while the radioactive phosphorus DNA could not -
The nobel prize in phsycology or medicine
For their discoveries concerning the molecular structure of nucleic acids and its significative for information transfer in living material