1. DNA, RNA & Protein Synthesis

2. A. DNA and the Genetic Code 1. DNA controls the production of proteins by the order of the nucleotides

3. 2. Watson & Crick discovered the double helix model of DNA

4. a. DNA is shaped like a twisted ladder and referred to as a “double helix” b. Sides- alternating sugars and phosphates bonded together by a strong covalent bond c. the sugar is deoxyribose (thus the name, deoxyribonucleic acid, or DNA)

5. d. Rungs-pairs of nitrogen bases (nucleotides) that always pair in the same way Adenine ↔ Thymine Cytosine ↔ Guanine Remember I am A t T he C ardinals G ame the bases are held together by a weak hydrogen bond

6. 3. DNA Replication a. Hydrogen bonds break, strands separate b. nucleus contains a “chemical pool” of free nucleotides that contain a sugar, phosphate and a base

7. c. free nucleotides match up with exposed bases d. Each strand of original molecule acts as a template for new DNA e. two identical strands are formed