9.9 Cell Cycle Flashcards
what does the cell do in G1 phase?
it gathers nutrients and energy. Lives and prepares
what does the cell do in the S phase?
it commits to duplication and division. DNA/organelle replication
what does the cell do in the G2 phase?
it checks and fixes DNA
DNA repair
what does the cell do in M phase?
divide
what are the three locations of the major cell cycle checkpoints?
G1/S transition
G2/M transition
metaphase/anaphase transition
what causes transition between G1 to S phase?
increase in CycE-Cdk2 levels
CycE-Cdk2 increase levels of what other cyclin?
CycA
CycA degrades _____ (what cyclin)
CycE
what does CycA do?
it induces DNA replication in S phase
CycB (inactivated) increases and is maximal before ____ phase. It degrades Cyc___.
M phase
CycA
CyB is regulated by phosphorylation by two enzymes: ______ and ______. Which inhibits and which activates?
CAK - activated
Wee - inhibits
to activate CycB, the inhibitory phosphate needs to be removed by _______.
Cdc25
what activated Cdc25 to dephosporylate the inhibitory phosphate on CycB?
complete and accurate DNA replication
once the inactivating inhibitory phosphate is removed from CycB, what phase transition can happen?
G2 –> M phase
what is the “anaphase wait” signal?
all kinetochores are attached with a microtubule and ready to split