BIOL 111 Lecture Notes - Lecture 19: Thymine, Guanine, Dna Mismatch Repair
Document Summary
Bacteriophages similar to chromatin made of dna and protein. Makes thousands of copies that inject dna and infect bacterial cells. Experiment showed that dna component of bacteriophages was the genetic material: james watson and francis crick. Proposed the double helix structure of dna in the 1950s: dna: structure. Dna and rna are polymers of nucleotides. Nucleotide: consists of a sugar, phosphate group, and a nitrogenous base. Phosphate group bonded to 5" carbon, and nitrogenous base bonded to 1" carbon: types of nucleotides. Four different types, only difference is their nitrogenous base. Bases are held together through hydrogen bonds. 2 dna strands are always antiparallel: template. Each strand of dna acts as a template for replicating its complementary strand. Daughter dna molecules, each consisting of one parental strand and one new strand. Have a small circular chromosome that is replicated starting at a single origin. Topoisomerase: controls damage of dna from untwisting dna.