What class of molecules are responsible for regulating the cell cycle?
The regulators of the cell cycle are proteins.
What are the two classes of regulatory proteins discussed in this section?
Cyclin-dependent protein kinases and cyclins.
Why do cyclins have their name?
Cyclins are called such because they undergo a constant cycle
synthesis and degradation. These changes signal cell cycle phase shifts.
Fill in the blanks: _________ binds to cyclin-dependent protein kinases
(Cdks) to activate them. Once activated, Cdks signal progression through the
cell cycle through _________, a process in which phosphate groups are added to
What is the name of the complex formed when mitotic cyclins bind to Cdks and
what is the role of this complex?
Activation of M-phase- promoting factor (MPF) is responsible for signaling
the entrance into M
phase. Its deactivation signals the exit from M phase.