Upload
milton-king
View
217
Download
1
Tags:
Embed Size (px)
Citation preview
6.1 DNA and the Code of Life
Pages 228-233
nuclein
• A name given to DNA when it was discovered by Friedrich Miescher in 1869.
Joachim Hammerling
performed experiments on Acetabularia to verify that the genetic material was in the nucleus.
image: taringa.net image: biologysemester58.wikispaces.com
Alfred Hershey and Martha Chase
1952- showed that viruses needed only to inject their DNA into a bacteria to produce more viruses.
Image: osulibrary.orst.edu
Phoebus Levene
1920’sDNA was composed of: A pentose sugar (cyclic, 5-carbon sugar) A nitogenous base A phospate group, PO4
3-
5 Carbon sugar
• Deoxyribose has one less oxygen atom than ribose.
Image: mun.ca
Phosphate group
PO43-
image: m2c3.com
Nitrogenous Bases
• Adenine, guanine, cytosine, thymine
Image: faculty.ccbcmd.edu
Erwin Chargaff
1940The amount of Adenine, A, is equal to the amount of Thymine, T.
The amount of Guanine, G, is equal to the amount of Cytosine, C.
Nucleotide
• DNA has a negative charge because of the phosphate ions in its backbone.
image: dnareplication.info
Rosalin Franklin
1951 X-ray crystallography: x-rays were aimed at a crystal of DNA to produce a diffraction pattern.
Image: cwp.library.ucla.edu image: shellemsbioblog.blogspot.com
James Watson and Francis Crick
• 1953 DNA model
Image: chemheritage.org
Complimentary base pairing
Image: dedunn.edublogs.org