DNAUnit Two

HISTORICAL DNA EXPERIMENTS

FREDRICK GRIFFITH (1928) Transforming principal of DNA

Bacteria are capable of passing genetic information to other bacteria

PHEOBUS LEVENE (1929) Characterized different forms of nucleic acids: DNA and RNA

Determined nucleic acids are made of: adenine (A), thymine (T), cytosine (C), and guanine (G)

OSWALD AVERY (1944) Determined that DNA is the material in which genes and chromosomes are made.

HERSHEY-CHASE EXPERIMENT (1952) Proteins were not the genetic material, DNA was

ROSALAND FRANKLIN (1951-1953) Research found picture of DNA X-ray crystallography Excluded from large discovery

WATSON AND CRICK (1953) Discovered the “double helix” structure of DNA

Published paper without mentioning Rosalind Franklin (CONTROVERSY)

ERWIN CHARGAFF (1959) Discovered three rules about DNA:

# of guanine equals # of cytosine # of adenine equals # of thymine # of A, T, C, G varies among species

BACKBONE (EDGES) Deoxyribose sugar

Phosphate group

NITROGENOUS BASES (MIDDLE)

Guanine Thymine

Cytosine Adenine