Learning Target 11: I can describe how the cell cycle is regulated by internal and external regulators under normal conditions . Learning Target 11
The Two Regulators: Internal External The Two Regulators (They both regulate the Cell Cycle)
Internal: Proteins that respond to events inside the cell are called Internal Regulators They allow the cell cycle to proceed only when certain processes have happened inside the cell Internal An example of an internal regulator is; Cyclin . Cyclins are rhythmic fluctuations in the activity of the cell cycle, which controls molecules pace the events of the cell cycle.
External: Proteins that respond to events outside the cells are called External Regulators External regulators direct cells to speed up or slow down the cell cycle External An example of an external regulator is; Platelet-Derived Growth Factors or PDGF. PDGF is essential for healing wounds. In this picture, PDGF is duplicating red blood cells to increase the healing process of whatever the injury may be.
References: Cell Division, Mitosis, and Meiosis http://www.uic.edu/classes/bios/bios100/lecturesf04am/lect16.htm Google Images http://www.chemie.uni-kl.de/forschung/lmctox/eisenbra/forschung/cyclin.jpg http://2.bp.blogspot.com/_WFsVtCoVVXQ/TRn1xtFUJvI/AAAAAAAACgg/LxkvxNJJpGU/s1600/Platelets_Coagulation_Blood_Cells_800px.jpg http://2.bp.blogspot.com/_HrsMw-at3Rs/TSddOuYIEcI/AAAAAAAAABw/uhMLVFeIewI/s1600/cellcycle2.jpg References