Discovery of DNA and DNA Structure Deoxyribonucleic Acid pp. 193-202

DNA Stores and transmits genetic information to make proteins Made up of repeating units of nucleotides

Griffith’s Experiments Showed that hereditary material can pass from one cell to another

Avery’s Experiments Showed that DNA is the hereditary material that transfers information between bacterial cells.

Hershey-Chase Experiment Confirmed that DNA, and not protein, is the hereditary material.

Watson and Crick & Franklin Determined the shape of DNA to be a double helix

Location Prokaryotes: floats in cytoplasm Eukaryotes: wrapped around proteins in the nucleus

DNA Structure Nucleotides have three parts: Deoxyribose Sugar Phosphate Group Base

Complementary Base Pairing Purine bonds to Pyrimidine A bonds to T G bonds to C

DNA Bases Purines: Two-ringed bases Pyrimidines: One-ringed Bases Adenine and Guanine Pyrimidines: One-ringed Bases Thymine and Cytosine

DNA Bonds Two strands (at the bases) are held together by weak hydrogen bonds. The sugar phosphate backbone is held together by covalent bonds

Double helix: DNA is double-stranded and coiled like a spiral staircase. Backbone is like the railing and the bases are the steps.