DNA: Information and Storage

I. Historical Background A. Gregor Mendel 1. Laws of Inheritance B. Thomas Hunt Morgan 1. The Chromosome Theory C. Frederick Griffin 1. Introduction to Transformation a. phenotype b. genotype c. allele d. dominant/recessive mode of inheritance 2. Modern molecular biological approach to bacterial transformation 3. Differential strains of S. pneumoniae to discover transformation D. Oswald Avery 1. Isolation of the transforming material E. Hershey and Chase 1. T2 Bacteria Phage 2. Radioactive labeling to track protein vs. dna 3. DNA as the genetic material F. Wilkins and Franklin 1. X-ray crystallography to study spacing/alignment of purified molecules 2. DNA structure a. right-handed double helix b. distance of bases c. helical turns d. width of helix G. Erwin Chargaff 1. Chargaff's rule for base pairing H. Watson and Crick 1. 5' to 3' anti-parallel arrangement 2. H bonding of nucleotide bases 3. Hydrophobic interactions (ladder rungs) 4. Sequence of nucleotides unrestricted 5. First Paper = First reported DNA structure 6. Second Paper = Proposed Semi-Conservative Replication I. Meselson and Stahl 1. 3 theories of DNA Replication a. conservative b. semi-conservative c. dispersive 2. Differential labeling of N to track parent and daughter strands II. Replication of DNA A. Origins of Replication 1. Initiating Proteins find the origin 2. 1000s of origins so that replication is rapid 3. The Replication Bubble 4. The Replication Fork a. where nucleotides are added b. always adds nucleotides to the 3' end and moves in the 5' to 3' orientation c. instability of the nucleotide triphosphate negative charges d. requires DNA polymerase e. leading and lagging strands f. Okazaki fragments g. DNA ligase B. Elongating the New DNA Strand C. Antiparallel Arrangement of Strands D. Priming of the DNA Synthesis and Accessory Proteins 1. RNA primer 2. Primase 3. DNA polymerase II 4. Helicase 5. Single-stranded binding proteins E. Proofreading and Repair of Mistakes 1. Use of excision by nucleases 2. DNA polymerase and ligase for repair