BIOL 331 Lecture Notes - Lecture 35: Chek2, Cdc25, Dna Replication
6 Apr 2018
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Document Summary
Normal cells can not process through the cell cycle if their dna is damaged. If cells override the cell cycle checkpoints with existing dna damage, this could lead to cancerous mutations. 1: repair of dna damage (although sometimes there"s more damage than can be repaired) 2: activation of a dna damage checkpoint, and arrest of the cell cycle. Only happens if cell cycle is paused. If the damage cannot be repaired during the time that the cycle is paused, cell undergoes apoptosis. Mechanisms to halt the cell cycle if: Dna replication in s phase (incomplete replication) Chromosome alignment during m phase (chromosomal misalignment) Ataxia-telangiectasia (at) and the response to double-strand dna breaks. Patients with at are sensitive to ionizing radiation, and have difficulties walking and coordinating. Atm is activated by double-strand dna breaks. Double stranded dna breaks are most detrimental to cells, and there is potential for other half of the strand to slip away once breakage occurs.
