BIOL 200 Lecture Notes - Lecture 7: Sister Chromatids, Spindle Apparatus, Histone H1
Document Summary
M-cdk(kinase) activated by cdc25: histone h1, condensin, mt-associated proteins, nucleolin. M-cdk activates apc, which degrades m-cdk: negative feedback loop. Blocking apc blocks activation of proteins to degrade cohesins. Higher order packing: chromatin fibre in chromosomal loops condensed(by condensins) into chromosomes. Mts are shorter and more dynamic in mitotic cells than interphase cells: how: more dynamic instability=more catastrophic events, associated proteins lead to catastrophe. Xkcm1 needed for depolymerisation: depolymerisation needed for proper spindle assembly. Metaphase: chromosomes aligned at equator, push and pull by rapid polarization/depolymerization. Anaphase: anaphase a: kinetochore mts get shorter, centromere/kinetochore pulled poleward first, anaphase b: interpolar mts lengthen, push poles apart, pules pushed and pulled apart, astral mts shorten, anaphase a and b happen simultaneously. Depolymerization of mts: bend, get closer to to minus end, attach, bend, release. Clicker: what would the effect of colchicine on chromosome mvmt during anaphase a and b: a: none, b: spindle poles could not be pushed apart.
