Editing Hysteresis (section)

==== Reversible hysteresis ====
[[File:Reversible_Hysteresis.png|thumb|Reversible hysteresis graph]]
A biochemical system that is under the control of reversible hysteresis has both forward and reverse trajectories. The system generally requires a higher [input] to proceed forward into the next bistable state then to exit from that stage. For example, cells undergoing [[cell division]] exhibit reversible hysteresis in that it takes a higher concentration of [[cyclin]]s to switch them from G2 phase into [[mitosis]] than to stay in mitosis once begun.<ref>{{cite journal |last1=Pomerening |first1=Joseph R. |last2=Sontag |first2=Eduardo D. |last3=Ferrell |first3=James E. |year=2003 |title=Building a cell cycle oscillator: hysteresis and bistability in the activation of Cdc2 |journal=Nature Cell Biology |volume=5 |issue=4 |pages=346&ndash;251 |doi=10.1038/ncb954 |pmid=12629549 |s2cid=11047458}}</ref><ref>{{cite journal |author1=Ferrell JE Jr. |author2=Machleder EM |date=1998 |title=The biochemical basis of an all-or-none cell fate switch in Xenopus oocytes |journal=Science |volume=280 |issue=5365 |pages=895–8 |bibcode=1998Sci...280..895F |doi=10.1126/science.280.5365.895 |pmid=9572732}}</ref>  Additionally, because the [cyclin] required to reverse the cell back to the G2 phase is much lower than the [cycilin] to enter mitosis, this improved the bistability of mitosis because it is more resistance to weak or transient signals. Small perturbations the [input] will be unable to push the cell out of mitosis so easily.