DNA is a Hereditary Material

Overview:

• DNA is arranged into chromosomes which contains genes'

• DNA is replicated

• Genes are transcribed into mRNA

• mRNA is translated into polypeptide

• Proteins control the working of organisms (traits or phenotypes)

Experiments

Griffith experiment:

• Something that is exchanged between the virulent and non-virulent bacteria

• Live pathogenic = mouse die

• Live non-pathogenic = mice live

• Heat-killed pathogenic = mice live

• Heat and live non-pathogenic - mice die and blood contains live pathogens

Hammerling experiment:

• Something (hereditary material) is in the nucleus

• DNA

• Proteins supporting it (histones)

Hershey-chase:

• DNA is a genetic material and not a protein

Levene and Chargaff:

• DNA is made of long chains of four nitrogen bases called nucleotides

• Pyrimidines: Cytosine (C) and Thymine (T)

• Purines are double-ringed and they are Adenine (A) and Guanine (G)

Watson and Crick:

• Structure of DNA

• Got this from Rosalind Franklins Xray picture.

DNA STRUCTURE

• Double helix

• Two strands of nucleotides held together by a lot of hydrogen bonds

• Double bond between A and T

• Triple bond between C and G