Eukaryotic cell cycle part 2 Flashcards
What does MITOSIS result in
2 daughter cells that are genetically identical to each other and the parent cell
(not 4 haploid)
What are the six phases of mitosis
look at the animation he has on canvas
IPPMAT interphase prophase prometaphase metaphase telophase(has cytokinesis in it)
What is mitotic spindle
4 different microtubules
4 microtubules of mitotic spindle
see figure slide 12
bipolar array of microtubules
interpolar microtubules
kinetochore microtubules
astral microtubules
Bipolar array of microtubules of mitotic spindle
+ ends radiate outward
– ends at spindle poles
interpolar microtubules
overlap other microtubules
kinetochore microtubules
+ end attached to kinetochore
astral microtubules
help position spindle in the cell
attached to centrosome
4 Microtubule-dependent motor proteins
see slide 12 bottom figure
Kinesin-5 (+ end)
Kinesin-14 (- end)
Kinesins-4/10 (+ end)
Dyneins
Kinesin-5 (+end)
push poles apart
kinesin-14 (-end)
pull poles together
Kinesin-4/10 (+ end)
chromokinesins
Associate with chromosome arms; push away from pole
chromokinesins
ability to associate with chromosomes during mitosis
dyneins (-end)
pull spindle poles away from each other
what is a centrosome
Microtubule-organizing center (MTOC) in animal cells
what is found in centrosome
centrioles (in pairs)
what is a centriole
Barrel shaped cylindrical structures in L-shaped configuration
development of spindle fibers in cell division
what happens to centrosome
duplicates when cell commits to division
S phase
after division how many centrosome are there
2- one at each pole during mitosis
what promote bipolar spindle assembly
mitotic chromosomes
what do the proteins associated with chromosome do
see slide 13
favor/encourage microtubule nucleation and stabilization
centrioles more info
2 bundles of microtubules; found in centrosomes
centromere (do not confuse with centrosome)
constricted region of chromosome
stages in interphase
G1,S,G2
G1 can have a G0 phase
what happens in G1 phase
cell growth
no replication
what happens in S phase
dna synthesis
what happens in G2
cell growth
where does cell spend most of its life
interphase (S)
when are chromosome duplicated
during S phase
2 sister chromatids
what things happen in interphase
dna replicated
centromere (constricted chromosome)
centrioles replicate
what happens when centrioles replicate
with Centrosomes Mitotic spindle formation
only in animal cells
are chromosome condensed in interphase
NO just constricted
when do chromosome condense
prophase
during prophase what forms
Mitotic spindle forms between centrosomes
they are not at the ends yet
Remember “eukaryotic chromosome organization” slide
find it on powerpoint
what holds sister chromatids together during prophase
cohesions the entire length
what is the next step in cell cycle at prophase
prometaphase
what happens in prometaphase
nuclear envelope breaks down
spindle fibers connect to centromeres
looks like one at each end
where do the spindle fibers connect to the chromosome centromere at
kinetochore
what is a spindle fiber
microtubule
what is a kinetochore
multilayered protein structure
goal of prometaphase
bi-orientation
chromosome connect to mitotic spindle
make sure one of each chromatid goes to different end
How does kinetochore sense correct attachment?
see slide 17
high levels of tension
Ndc80 complex
connects microtubule to kinetochore
what phase comes after prometaphase
metaphase
goal of metaphase
starts with m
Meet in the middle
chromosome line up in middle
How do they know to meet in the middle
Depolymerization of microtubules at + end (at kinetochore)
Microtubule flux
Polar ejection force (polar wind)
what is microtubule flux
Microtubules pulled toward spindle poles
Microtubule length is constant (depolymerize at – end, polymerize at + end)
what causes the polar wind
motor proteins
what is the next phase of cell cycle
anaphase
