DNA Discovery

  • Mendel's rediscoveres

    Genetic information was carried on the chromosomes in the eukaryotic cells and that the two main components of chromosomes are DNA and protein.
  • DNA structure and Nucleotides

    are the subunits of nucleic acids and consists of a five-carbon sugar, a phosphate group, and a nitrogenous base.
    DNA nucleotides contain sugar deoxyribose, a phosphate, and one of four nitrogenous bases:
  • Griffid

    One stain could be transformed, or changed into the other forms, studied two strains of the bacteria Steptococcus pneumoniae, which caused pneumonia.
  • Avery

    Oswald Avery and its collegues identified the molecule that transformed the R strain of bacteria into the S stain,
  • Chargaff

    analyzed the amount of denine, guanine, thymine, and cytosine in the DNA of various species.
    Chargaff rule: C=G and T=A
  • x-ray diffraction

    DNA was a doble helix, or twisted label shape, formed by 2 strands of nucleotides twisted around each other.
    DNA is the genetic material of all organisms, composed of two complementary precisely paired strands of nucleotides wound in a double helix.
  • Watson and Crick

    they measured the width of the helix and the spacing of the bases.
    some important features are:
    two outside strands consist of alternatind dioxyribose and phosphate
    cytosine and guanine bases pair to each other by three hydrogen bonds
    thymine and adenine bases pair to each other by two hydrogen bonds
  • DNA structure

    is often compared with a twisted ladder.
    cytosine and thymine are pyrimidinebases, adenine and guanine are purines and C=G and A=T.
  • Orientation

    carbon molecules can be numbered in organic molecules
    the orientation of the two strands is called antiparallel.
  • Hershey and Chase

    DNA is the transforming factor,
    bacteriophage is a type of virus that attacks bacteria,
    DNA is the genetic material
    Viruses can not replicate themselves.
    used the technique called Radioactive labelling to trace the fate of the DNA
    proteins contain sulfur and DNA doesnt.
  • The anouncement

    DNA works as a genetic code.