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Dive into the intriguing world of DNA history, structure, and significance. Explore Griffith’s transformative bacteria experiment, Chargaff’s findings, Rosalind Franklin’s crucial contributions, and Watson and Crick’s groundbreaking discovery of DNA structure. Uncover the secrets of nucleotides, base pairing, and the fascinating process of DNA replication.
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Check out Griffith’s experiment on page 138 • What is up? • Shows how harmless bacteria can turn deadly. • How? DNA is transferred!
DNA(de-oxy-ribo-nucleic acid)a nucleic acid that stores and transmits the genetic information from one generation to the next
Big Players in DNA • Chargaff • Rosalind Franklin • Watson and Crick
People knew that DNA was made up of: • Adenine (A) • Guanine (G) • Cytosine (C) • Thymine (T)
Erwin Chargaff • Discovered that in any sample of DNA, the amount of A equals the amount of T and the amount of C equals the amount of G. • This suggested that A binds with T and that C binds with G.
Rosalind Franklin’sX-Ray Crystallography • Took x-ray photographs of crystallized DNA • Discovered that the shape of DNA must be a helix, because of the x-ray pattern • Died of cancer (too many x-rays?)
Watson and Crick • Credited for discovering the structure of DNA in 1953 • Used Chargaff and Franklin’s discoveries along with toy models to discover the structure
NUCLEOTIDES Made up of: • A phosphate group • 5 carbon sugar • Nitrogenous Base (nitrogen containing)
PURINES • Adenine (A) • Guanine (G)
PYRIMIDINES • Cytosine (C) • Thymine (T)
Base Pairing in DNA A-T C-G
Write the complementary DNA strand for each of these DNA strands: • DNA • GAATTACA • CCAATTAG • ATAGACAG • CCAGTACA • DNA • CTTAATGT • GGTTAATC • TATCTGTC • GGTCATGT