History and Discovery

By dgnz09

  • Discovery of Nucleic Acids

    Discovery of Nucleic Acids
    It was discovered by Friedrich Miescher
    He called nucleic from the nuclei of pus cell.
    Working with salmon leukocytes and spermatozoa, he obtained a substance rich in carbon, hydrogen, oxygen, nitrogen and a high percentage of phosphorus. This substance was originally called nuclein, because it is found in the nucleus.

  • Discovery of DNA Components

    Discovery of DNA Components
    It was discovered by Phoebus Leven.
    He proposed that DNA was made up of equal amounts of adenine, guanine, cytosine, and thymine.
    The period that he was investigating was 1900 to 1929

  • Levene's Tetranucleotide

    Levene's Tetranucleotide
    It was developed by Levene and proposed that DNA was composed of repeating sequences of four nucleotides. Showed that the four frequencies were not same, according to his rules the correct relationship is G = C ≠ A = T.

  • Frederick Griffith

    Frederick Griffith
    Proposed the first widely of bacterial transformation. Which led to the discovery that DNA acts as the carrier of genetic information.

  • Avery, MacLeod and McCarty

    Avery, MacLeod and McCarty
    They determined what actually caused the transformation. Demonstrated that DNA from a virulent smooth strain of pneumococcus could transform a rough strain into the smooth variety. This experiment concludes that DNA is the genetic material

  • Journal of Experimental Medicine

    Journal of Experimental Medicine
    Studies on the Chemical Nature of the Substance Inducing Transformation of Pneumococcal Types: Induction of Transformation by a Deoxyribonucleic Acid Fraction Isolated from Pneumococcus Type III.

  • Helix

    Helix
    Double Helix:
    Watson and Crick described DNA as a double helix, at the centre there are sugars and phosphates and outside facing the nucleobases.
    Trple Helix:
    Linus Pauling and Robert Corey proposed a triple helix structure for DNA.

  • Counting nucleobases

    Counting nucleobases
    Erwin Chargoff was counting by using UV spectroscopy and paper chromatography.
    Amounts of Adenine = Amounts of Thymine
    Amounts of Cytosine = Amounts of Guanine

  • Hershey-Chase Experiments

    Hershey-Chase Experiments
    In her experiments he used phages and radiolabeled phosphorus and sulfur. Hershey and Chase concluded that DNA was the genetic material. Protective protein coat was formed around the bacteriophage

  • The nobel Prize in Physiology or Medicine

    The nobel Prize in Physiology or Medicine
    Watson and Crick's discovery is based on a theory developed by Franklin, however by the time Watson, Crick and Wilkins received the Nobel Prize