Notes on the Discovery of DNA Structure and Function

Mendel: Conducted experiments with peas showing inherited traits linked to genes.

Miescher: isolated 'nuclein' from cell nuclei, later known as nucleic acid.

Levene: Isolated two types of nucleic acids (RNA - ribose sugar, DNA - deoxyribose)

Hammerling: Studied Acetabularia, concluding that the nucleus contained genetic information.

Griffith: showed the phenomenon of passing on genetic material, called it “transformation”

• live pathogenetic material = death

• dead pathogenetic material = no effect

• non-pathogenic material = no effect

• mixed dead pathogenic and live non-pathogenic material = death

Avery, MacLeod, and McCarty: Confirmed that DNA is the transforming agent by treating bacteria with enzymes

Avery: proved that genes were made of DNA by moving nucleic acid, causing disease from one strain of bacteria to another

Chargaff's: A - T and G - C, ensuring consistent length for the base pairs in the double helix.

Franklin and Wilkins: took the first photo of DNA using x-rays and confirmed its double-helix shape

Watson and Crick: suggested the specific pairing allows for copying of genetic material, whereby DNA could unzip during cell division, producing identical daughter strands.

Hershey and Chase: confirmed DNA as the hereditary material by using T2 virus to infect E. coli, marking DNA with radioactive phosphorus and protein with sulfur. Found that only radioactive phosphorus entered the bacteria.

Watson and Crick: established the double helix structure with a phosphate backbone and base-pairing.