Which of the following molecules is maintained at a relatively constant level throughout the cell cycle but requires a cyclin to become catalytically active?
A) PDGF
B) MPF
C) cyclin
D) Cdk

Question

Quizplus · Accepted Answer

Cdk (Cyclin-dependent kinases) are maintained at relatively constant levels throughout the cell cycle but require binding to a cyclin to become catalytically active. Cyclins regulate the cell cycle by activating Cdks, and their levels fluctuate, unlike the constant level of Cdk.

Which of the Following Molecules Is Maintained at a Relatively