Cell Division Flashcards
what is the cell cycle critically controlled by?
cdk - cyclin-dependent kinases
when is cdk activity at its peak?
during mitosis
what is cdk regulated by?
+ phosphorylation
+ dephosphorylation
which cdk complex controls events in S phase of cell division?
active S-cdk
which cdk complex controls events in M phase of cell division?
cdk1 = cdc2
which cdk complex controls events during G1 phase of cell division?
cdk4/6
which cdk complex controls events between R point of G1 and start of S phase of cell division?
cdk2
which cdk complex controls events from start to middle of S phase of cell division?
cdk2
which cdk complex controls events from mid S phase M to end of G2 phase of cell division?
cdk1 = cdc2
how many checkpoints are there in G1?
- damaged DNA
2. unfavourable extracellular environment
how many checkpoints are there in S phase?
- damaged or incompletely replicated DNA
how many checkpoints are there in G2?
- damaged or incompletely replicated DNA
how many checkpoints are there in M phase
- chromosome improperly attached to mitotic spindle
when is the checkpoint for growth or quiescence?
R-Point (G1/S transition)
what disease can defects in cohesion cause?
Roberts Syndrome
- very rare
how are sister chromatids held together?
cohesion complex/rings made of cohesin
what do defects at spindle checkpoint cause?
aneuploidy
which cyclin controls events in M phase of cell division?
cyclin B
which cyclin controls events during G1 phase of cell division?
cyclin D
which cyclin controls events between R point of G1 and start of S phase of cell division?
cyclin E
which cyclin controls events from start to middle of S phase of cell division?
cyclin A
which cyclin controls events from mid S phase to end of G2 phase of cell division?
cyclin A
what is the role of p53 in DNA damage?
directs transcription of cdk-inhibitors
what is CHK2 activated by?
DNA damage
