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G2/M Transition

The transition from the G2 phase to mitosis, triggered by the activation of CDKs and the degradation of cyclins, preparing the cell for division.
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The statement of the theorem

Consider the concentrations of key regulatory proteins: Cyclin B (CBC_B), CDK1 (DD), and the inhibitory phosphatase PP\text{PP}. The G2/M transition is modeled by the activation of CDK1, which requires the formation of the active complex D∙CBD \bullet C_B. The rate of complex formation and subsequent phosphorylation (P\text{P}) is described by the following system of coupled differential equations:\nd[D∙CB]dt=kform[D][CB]−kinact[D∙CB]⋅(1−[P][P]max)\frac{d [D \bullet C_B]}{d t} = k_{form} [D][C_B] - k_{inact} [D \bullet C_B] \cdot \left( 1 - \frac{[P]}{[P]_{max}} \right) \nwhere kformk_{form} is the association rate, kinactk_{inact} is the inactivation rate, and the term (1−[P][P]max)\left( 1 - \frac{[P]}{[P]_{max}} \right) represents the inhibitory effect of phosphatases, driving the system towards the mitotic state when [P][P] drops below a critical threshold.
Source: Wikipedia