Biology 2581B Study Guide - Quiz Guide: Origin Recognition Complex, Dna Replication, Reverse Transcriptase
3 Jun 2020
School
Department
Course
Professor
Document Summary
Orc = origin recognition complex, is inactive when phosphorylated most newly assembled nucleosomes are hybrids of old" and new" histones. End replication problem = during each round of replication the final rna primer cannot be replaced by dna (there is no 3" oh-group) nucleotides are lost at each cell division and thereby information is lost. Prokaryotes have circular dna and do not have this problem. Repair enzymes: to repair damage caused by outside forces. Spontaneous" lesions = thermodynamically (depurination, depyrimidination, cytosine deamination: hydrolysis: with h2o, a purine or an amine group is taken away. Induced" lesions = chemically, physically: chemical (external and internal): free radicals, environmental chemicals, reactive metabolites, physical (external): uv radiation, radioactivity, smoking. Depurination of a leads to deletion of the base pair. Unnatural" bases = recognizable difference compared to original dna bases. Deamination of c leads to u, this can be identified as unnatural as dna has t not u.
