Explain the terms interphase and M-phase with regard to the cell cycle. A central control system triggers progression through essential control points in the cell cycle. Define the 2 classes of cyclins and what checkpoints they act upon. Explain the mechanism by which MPF becomes activated and deactivated. Explain the function of feedback inhibitors on the checkpoints of the cell cycle.
Human cells have a similar but more complex mechanism of cell cycle regulation than yeast cells.
Explain the existence of multiple isoforms for the G 1 -S cyclins and Cdks. Inhibitors of cell cycle progression function with stimulators of cell cycle progression. Explain the relationship between the interaction of Rb protein with the transcription factor E2F and the state of phophorylation of the Rb protein. Explain how Rb protein becomes phosphorylated and dephosphorylated. Explain how a DNA virus can regulate the mammalian cell cycle.