DNA Deoxyribonucleic acid What is it??? DNA is a biomolecule it contains your “genetic code” (instructions for all inherited traits)

DNA DNA is made of….. 3 parts of a nucleotide: 1. 2. 3. ….nucleotides Phosphate group A sugar, called deoxyribose ….nucleotides A nitrogenous base such as: Adenine Thymine Cytosine Guanine

DNA The nucleotides join together to make a double stranded molecule of DNA (double helix). -What connects the nucleotides? -Which part of the nucleotide makes up the “backbone” of the DNA? -Which part of the nucleotide contains your “code” for inherited traits? Hydrogen bonds Phosphate and sugar The order of the nitrogen bases

Chagraff’s base-pair rule Adenine pairs with Thymine and Cytosine pairs with Guanine % of Adenine = % of Thymine % of Cytosine = % of Guanine If there is 20% Adenine, what percent thymine? what percent cytosine? what percent guanine? 20% 30%

Try this….. If one strand of DNA contains this code…… ATC GGC CAT TGC CCA AAG CGA TCA TAG CCG GTA ACG GGT TTC GCA AGT The other strand would be….

Watch This… http://www.youtube.com/watch?v=gqvYOr78THo