Unformatted text preview: of DNA=replication).
S – phase when DNA is replicated (Histones are only proteins being made here.)
G2 – short phase when cells prepare to undergo mitosis and cytokinesis
M – phase of chromatin condensation into chromosomes and equal separation
between two daughter cells (M is further subdivided.) Transitions from one cell cycle phase to the next are controlled by levels of
proteins called cyclins and cyclin-dependent kinases, which together
proteins called CYCLINS and their CDKs control cell cycle!!!!! Control transition
constitute cell cycle “checkpoints.”
bw phases of the cell cycle at CHECKPOINTS.
Fig. 3-13 DON'T HAVE TO MEMORIZE THIS TABLE. When each successive set of activities for a phase is completed, the cyclin
controlling that cell cycle phase is removed rapidly by proteasomes and a new
cyclin that promotes different activities (enzymes) for the next cell cycle phase
Cyclins QUICKLY gotten rid of so that
cell cycle can keep moving! Cyclins get UBIQUITINATED and moved to proteasomes to be broken down!!!
Then they're DONE. Then Diff cyclin is turned on by a kinase and does their activity.
When THAT'S ﬁnished, cells says "okay, every...
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