Cell Division Cycle Flashcards
histone synthesis, synthesis of enzymes required for DNA replication, replication of DNA from multiple replication origins, removal of licensing factors, and duplication of centrioles all happen in which phase of the cell cycle?
S phase
Prophase
Xs condense
kinetochores assemble onto centromeres
spindle forms
Prometaphase
nuclear envelope breaks down
spindle invades nucleus
kintochores capture MTs
_____ attachment of spindles results in equal ______ on chromosomes from both spindle poles at the metaphase plate
bipolar
tension
What happens when the Anaphase Promoting Complex is activated?
cohesins break dows
chromatids can separate
Telophase
nucleus reforms
division of cytoplasm begins with formation of contractile ring
what are the three major checkpoints of the cell cycle?
G1/S Start
G2/M
Exit M Anaphase/Metaphase
What do Ckd’s do?
mediate cell cycle
S-Cdk –> triggers DNA replication machinery
M-Cdk –> triggers mitosis machinery
How is an active Cdk-cyclin complex turned off?
- E3 ubiquitin ligase ubiquitinates cyclin
- cyclin is destroyed by proteolysis in proteosome
- activating phosphate on cyclin is removed by phosphatase
what happens to p53 if there is no DMA damage in cell?
degraded in proteasome
what does p53 do if there is damaged DNA in the cell?
phosphorylated and activated
blocks entry to S phase
apoptosis
concentration/amount of ______ is most carefully regulated during each cell cycle
nuclear genomic DNA
how does cytokinesis work?
microfilaments form contractile ring
force for contraction of ring comes from non-muscle myosin ATPase
what event triggers cells to pass through the metaphase/anaphase chekcpoint?
tension on all of the kinetochores form bipolar microtubule attachment
