DNA: The Code of Life

DNA vs. Protein 1920s- DNA structure wasn’t known People thought proteins carried info b/c they are complex Experiments used to determine DNA was the code: 1928- Frederick Griffith worked with type R and type S pneumonia strains.

Conclusion: R strain transformed dead S into live to kill the mouse.

Bacteriophage- virus affecting bacteria. Conclusion- DNA entered bacteria, but not protein

Why is DNA important? Determines our traits (proteins) Used to solve crimes and determine identities. Ex: Who was Anastasia and Ted Kaczynski?

Who discovered DNA? James Watson, Francis Crick (noble prize- 1953) Maurice Wilkins- lab help Rosalind Franklin- woman who discovered DNA was a double helix using x-ray crystallography.

Maurice Wilkins DNA helix from x-ray crystallography Rosalind Franklin

Structure of DNA- Deoxyribonucleic Acid Cell nucleus chromosome gene DNA nucleotide phosphate, sugar, nitrogenous base Double helix

Partners for life- AT, CG Held together by weak hydrogen bonds Antiparallel strands

DNA Replication Why? So each cell has copy of genes during mitosis. Animation of DNA replication!

DNA Animations http://www.ncc.gmu.edu/dna/repanim.htm http://www.pbs.org/wgbh/aso/tryit/dna/shockwave.html http://science.nhmccd.edu/biol/bio1int.htm E-Bio @ Horton

Protein synthesis animation http://science.nhmccd.edu/biol/bio1int.htm#protein E-Bio @ Horton Transcription to Translation