Discovery of DNA Structure Notes and Scientists

He discovered a new compound called nuclein (later called DNA) in the cells nucleus of White Blood Cells. (DNA is high in Nitrogen and Phosphorus).

1869 - Friedrich Miescher

1885 - 1901 Albrecht Kossel

Described the nitrogen bases in nucleic acids.

1909 - 1929 Phoebus Levene

Found that DNA is made of monomers of phosphate-sugar-base which he called nucleotides.

1940-1950s Linus Pauling

Revolutionized molecular modeling in biology → these techniques were used by Watson & Crick.

1950 Erwin Chargaff

The amount of A, T, C, G, in DNA varies from species to species. The amount of A=T & G=C.

Write 3 things about purines and pyrimidines:

A and G are purines with 2 rings. C and T are pyrimidine with 1 ring. Purine binds with a Pyrimidine.

1950 Maurice Wilkins

Discovered that DNA has a crystalline structure can be X-ray crystallography.

1952 Rosalind Franklin

X-ray crystallography expert took photos! (Clear diffraction image of DNA).

hydrophobic, hydrophilic

Bases are -. Sugar + phosphate are -.

Adenine, Cytosine, Guanine, Thymine.

List the 4 DNA nitrogen bases

hydrogen bonds, weak, nucleotides, Double Helix, (Deoxyribose)/phosphate, outside, backbone, inside, Complementary base pairing, two, three.

Major features of DNA: Joined by - - (-). Made of -. Structure: - -. Sugar: (-)/- are on the -; called the -. Nitrogen bases are on the -. Type of base pairing: - - - : A-T have - bonds. G-C have - bonds.

(H) strands are directionally defined by carbons on deoxyribose (5’ and 3’).

5’ → down 3’ Antiparallel 5’ → up 3’

Describe (H) strands: (2 things)