BIOL 2100 Chapter 12.3: 12.3 Biology 2100 Textbook Notes
7 Oct 2016
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12. 3 the eukaryotic cell cycle is regulated by a molecular control system. Cell cycle control system cyclically operating set of molecules in cell that triggers and coordinates key events in cell cycle. Checkpoint- control point in cell cycle where stop/go signals regulate the cycle: found in g1,g2 and m phases (3) Cell cycle clock: cyclin dependent kinases (cdks) Activated by being attached to a cyclin. Its activity depends on concentration of cyclins: cyclins. Concentration of this fluctuates: mpf cyclin-cdk complex. Triggers cells passage into m phase past g2 point. Cyclins accumulate during g2 and associate with cdks. Switches itself off during anaphase by destroying its own cyclin: cyclin levels rise during s and g2 phases, and fall during g1 phases. If cell receives go ahead signal, it completes the rest of the phases. If cell receives stop signal, the cell exits the cycle and switches to nondividing phase (g0: internal signal occurs at m phase checkpoint.
