BIOCHEM 2EE3 Chapter Notes - Chapter 22: Nucleophilic Substitution, Escherichia Coli, Nucleophile
Document Summary
Chapter 22 dna replication: watson-crick predicted 3 things abt dna repl. : it is semiconservative; replication happens at a fork where the parental strands are unwound and daughter strands are synthesized; and that rep. begins at more than one replication origins on a chromosome. In 1963 john cairns labelled replicating dna in e. coli and grew bacteris in medium with 3h thymidine: then he took out a long circ. Molecule from the e. coli and put it under a microscope found 2 rep. forks. It looks like a hand holding a cylinder: gene that codes for dnap i is pola, discovery of additional polymerases, dnap iii used in nucleotide addition during replication. It has a high vmax which flows with the high replicative dna chain growth rate: functions only @ replication forks so there are less than 10 of these molec per cell. Dnap i but was able to synthesize the small n-terminal frag.