BIOL 2021 Chapter Notes - Chapter 17.4: Sister Chromatids, Cdc20, Separase
11 Feb 2018
School
Department
Course
Professor
Document Summary
Dyneins: minus-end directed and pull microtubules to the cortex and away from each other. Kinesin 5: plus-end directed and push the poles apart: interact with the plus ends of antiparallel microtubules in the midzone. Kinesin 14: minus-end directed and pulls the poles together: forces are balanced, crosslink antiparallel interpolar microtubules at the midzone. Kinesin 4,10/chromokinesins: plus-end directed and carry chromosomes to the plus ends. Kinetochore: attachment site on chromosomes: proteins at the centromere, there are 2 kinetochores per chromosome one for each chromatid. Q: how many kinetochores are there in a human cell at mitosis? (we have 23 pairs of chromosomes) Microtubules capture chromatids that are connected to opposite poles and are lined up on the metaphase plate (equator) Cohesin: holds sister chromatids together at the end of s phase: the destruction of cohesion allows chromatids to separate, apc activation triggers anaphase, cdc20 activates apc. Separase: enzyme that cuts cohesin to separate sister chromatids.
