BIOC 300D2 Lecture Notes - Lecture 2: Phosphodiester Bond, Scattering, Tautomer
8 Jul 2016
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Lecture 1: lab 7 lundi 11 janvier 2016. Dna looks in this condensed (chromosome) form only for a short period of cycle. Half of dry weight of chromosomes are proteins. Light-band tends to be gene-rich while dark- band tends to be gene poor. Main interaction between dna and proteins: histone optomer core. The backbone of dna is negatively charged due to phosphate while the histones are positively charged. The only way to getting rid of this interaction without completely messing up your dna is using high salts. You have to package 2 m of genetic material to the size of a nucleus in a way still physiologically accessible (genes still expressed, transcribed, tfs still need to bind in there, In the living cells, all nucleic acids are complexed with proteins. The complex is usually held together by ionic interactions, i. e. the complexing proteins are basic. This interaction is ph and ionic strength sensitive! (take advantage of when purifying dna)
