BIOL 1000 Lecture Notes - Lecture 19: Erwin Chargaff, Crystallography, Base Pair
Document Summary
Genetic material: found in chromosomes, between cell division it is called chromatin, during cell division it coils & condenses and is called a chromosome. Dna is a double helix: has a sugar-phosphate backbone, base- pairs form steps , a-t, c-g. Erwin chargaff (1949: analyzed base composition of dna and discovered that, amount of a= amount of t, amount of g= amount of c, the propositions of a relative to g differ from one species to another. Rosalind franklin (early 1950s: made and studies x-rays crystallography images of dna, her x-ray diffraction results provided crucial structural information about dna. Watson and crick, with maurice wikins (1953: proposed the structure of the dna double helix (ball & stick model of dna) *number & sequence of nucleotides is unique to each different kind of dna molecule. *complementary base pairing- forms the double-stranded dna molecule.