BIOLOGY 2.6
EMILY KINZLER
, EUKARYOTIC CELL CYCLE
cells reproduce by duplicating content + split to 2 daughter cells
m phase - nuclear + cytoplasmic division
interphase - between each m phase, where prep for cell division with checkpoints
CELL CYCLE + ITS REGULATION
CELL CYCLE CHECKPOINTS
g1/s checkpoint - restriction point
g2/m checkpoint -
checkpoints prevent uncontrolled division leading to tumours + detect + repair damage
to DNA (e.g. caused by uv light)
REGULATION OF EUKARYOTIC CELL CYCLE as events controlling cell cycle occur in specific sequence, ensures that cycle cant be
reversed + dna only duplicated once during each cycle
!
m phase - checkpoint chemical triggers condensation of chromatin, halfway through
cycle metaphase checkpoint ensures cell ready to complete mitosis, cell growth stops,
nuclear division (prophase, metaphase, anaphase, telophase), cytokinesis
g0 phase - resting phase triggered in early g1 at restriction point by checkpoint
"
chemical, apoptosis/differentiation/senescence, can remain in this phase indefinetely
g1 phase - growth phase, checkpoint control mech ensures cell ready to enter s phase
+ begin dna synthesis, cells grow + inc in size, transcription of genes (to make rna),
organelles dupliate, biosynthesis (protein synth, making enz needed for dna rep in s
phase), p53 (tumour supressor) gene controls this phase
s phase (of interphase) - committed to completing cell cycle, dna replicates, when all
chromosomes duplicated theres identical sister chromatids, rapid as dna base pairs
more susceptible to mutagenic agents so reduces chance of spontaneous mutations
g2 (of interphase) - chemicals ensure cells ready for mitosis by stim proteins that r
involved in making chromosomes condense + form on spindle, cells grow
EMILY KINZLER
, EUKARYOTIC CELL CYCLE
cells reproduce by duplicating content + split to 2 daughter cells
m phase - nuclear + cytoplasmic division
interphase - between each m phase, where prep for cell division with checkpoints
CELL CYCLE + ITS REGULATION
CELL CYCLE CHECKPOINTS
g1/s checkpoint - restriction point
g2/m checkpoint -
checkpoints prevent uncontrolled division leading to tumours + detect + repair damage
to DNA (e.g. caused by uv light)
REGULATION OF EUKARYOTIC CELL CYCLE as events controlling cell cycle occur in specific sequence, ensures that cycle cant be
reversed + dna only duplicated once during each cycle
!
m phase - checkpoint chemical triggers condensation of chromatin, halfway through
cycle metaphase checkpoint ensures cell ready to complete mitosis, cell growth stops,
nuclear division (prophase, metaphase, anaphase, telophase), cytokinesis
g0 phase - resting phase triggered in early g1 at restriction point by checkpoint
"
chemical, apoptosis/differentiation/senescence, can remain in this phase indefinetely
g1 phase - growth phase, checkpoint control mech ensures cell ready to enter s phase
+ begin dna synthesis, cells grow + inc in size, transcription of genes (to make rna),
organelles dupliate, biosynthesis (protein synth, making enz needed for dna rep in s
phase), p53 (tumour supressor) gene controls this phase
s phase (of interphase) - committed to completing cell cycle, dna replicates, when all
chromosomes duplicated theres identical sister chromatids, rapid as dna base pairs
more susceptible to mutagenic agents so reduces chance of spontaneous mutations
g2 (of interphase) - chemicals ensure cells ready for mitosis by stim proteins that r
involved in making chromosomes condense + form on spindle, cells grow
