Exam 4 Part 2 Flashcards
mitogens
bind to receptor to create a signaling pathway that has an effect on cell proliferation
Rb protein
transcription regulator that can be activated by a mitogen
survival factors
activate a signaling pathway that blocks cell death
Bcl2 gene
activated by survival factors that blocks apoptosis
Growth factors
(In bovine serum) - signals a pathway to lead to cell growth (not necessarily proliferation)
microtubules in cell division
make up the mitotic spindle
kinetochore microtubules
interpolar microtubules
aster microtubules
micofilaments in cell dvision
actin and myosin make up the contracile ring
phragmoblasts
in plants - vesicles that start the building of a cell wall
kinetochore microtubules
physically attach to chromosomes and pull them apart
aster microtubules
keeps attached to and anchors centrosomes
interpolar microtubules
uses a pushing actin with dynein to push apart cells
also need to lengthen to continue the movement
why do cells die?
for development (fingers), neuronal cells need to die for proper communications, cell infected with a virus and kills itself to stop spread - epithelial cells shed - frog development from tadpole
When is cell dead?
Cell has lost plasma membrane integrity (with incorporation of dye)
Cell and nucleus has undergone complete fragmentation into descrete bodies
Corpse or fragments have been engulfed by an adjacent cell in vivo
necrosis
mechanical cell death from damage
spills contents into surroundings which can damage other cells
apoptosis
choice to undergo death
usually clean and compartmentalized
doesn’t damage neighboring cells
allows from recycling of components
intrinsic apoptosis
cell senes something wrong within cell and signals death
DNA damage, ER stress, too short telomeres, etc
extrinsic apoptosis
signals from outside environment signals death
procaspase
cleaved through proteolysis and signaled to cleave by an extrinsic apoptosis receptor
cleavage of these activates and commits the cell to death
can activate more caspases or other things for death
proteolysis
cleavage of procaspases to start apoptosis
Bax/Bak
two different activating proteins that are stimulated by intrinstic apoptosis. Causes mitochondria to release cytochrome C
cytochrome C
e transporter in mitochondria. Leaves the organelle by Bax/Bak signaling.
Bind to an adaptor protein which assembles into an apoptosome
apoptosome
assembly of adaptor proteins attached to cytochrome C -and procaspase 9
activated by proteolysis of procaspase 9 to continue apoptosis
