BIO 3170 Lecture 15: BIO3170 midterm 1 review 3
20 Dec 2018
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Document Summary
Hs acetylation loosen promote geneexpression chromatin structure remove to nucleosome s adjacent nucleosome on nucleosome t attraction of tail. Important role in recruiting other proteins1 readers to dna. Repression i. e trimethylation of lys on h3 recruits heterochromatin specific protein. Activation i e acetylation recruits transcription factors promotegeneexpression. Barriers chain like manner specificdna sequences that mark border of heterochromaticregions attract proteins which act as physical barrier attract modifyingenzymes which promote desired chromatinformation i e hs4 attract histone transferase. Objective: describe the concepts of positional effect variegation and of positional effect. Describe how heterochromatin can be inherited when cells divide. Positional effect genes 0expressed if inserted too close or in region of heterochromatin. Positional effect variegation in vivo chromosome breakage rejoining can also move genes f allow heterochromatic state to spread dynamic. Objective: describe the concept of the histone code & explain how centromeres are an example of this. Objective: distinguish the function of some dna polymerases family members.
