Apoptosis Flashcards
what is apoptosis
programmed cell death
what are the two forms of apoptosis
Intrinsic apoptosis: signals from within the cell trigger apoptosis
Extrinsic apoptosis: signals from outside the cell trigger apoptosis
what happens to the cell during apoptosis
-The cell shrinks and its contents condense
-the nuclear envelope breaks up
-the cell blebs into smaller apoptotic bodies
-the cell is engulfed and digested by phagocytes
why is it important that the destruction of the cell is regimented process
if the fragments entered the extracellular space they could trigger an immune response which could harm the greater organisms
what molecule triggers intrinsic apoptosis
trophins
either the presence of pro-apoptotic trophins or the absence of anti-apopotpic trophins
what is the effect of trophin on nerve cells
nerve cell development is massively impacted by trophin levels.
nerve cells will only survive if they receive enough trophin signals. Only nerve cells that make connections receive trophin meaning the rest will apoptose
what is the role of the Bcl-2 family of proteins in apoptosis
these are the main regulator proteins of apoptosis deciding whether the cell should live or die. Bax Bak and Bak proteins form channels that allow Cyt-C into the cell causing apoptosis whilst Bcl-2 and Bcl-xl prevent these channels form forming
what is the role of APF-1 in apoptosis
this is the main adaptor protein in intrinsic apoptosis. the signal for the cell to apoptose, Cyt-C is carried by APF-1 to activate capsin-9, triggering the transduction
what is the role of mitochondria in intrinsic apoptosis
mitochondria produce a signal called cytochrome-C. This is releases into the cell through channels formed by the Bcl-2 family of proteins in the absence of trophins. this causes apoptis
what is DISC
a complex that cleaves procaspase 8 during extrinsic apoptosis
