Exam 2 Ch 18 Flashcards
What are the 2 forms of cell death
Apoptosis and Necrosis
What happens during Apoptosis (general)
*cells shrink and condense
*cytoskeleton collapses
*nuclear envelope disassembles
*nuclear chromatin condenses and breaks up into fragments
*Plasma membrane bulges outwards and forms apoptotic bodies that get phagocytosed by macrophages
What is the general purpose of Apoptosis
*Shape the hands and feet during development
*Quality control to eliminate cells that are abnormal, misplaced, nonfunctional, or dangerous to the organism (remember, DNA damage induces apoptosis!)
Can apoptosis be stopped once started
NO
What is the necrosis (general)
Cell death due to trauma or lack of blood supply
cells swell and burst (it’s messy!!)
Spill their contents over to their neighbors and initiate inflammatory responses
What is capase
Specialized protease that is held inactive within the cell UNTIL an apoptotic signal is received
What are the two types of caspases
Initiator and Executioner
What does initiator caspases do
Begins the apoptotic process
What is the only thing the initiator caspases cut
Executioner caspase
What does the Executioner caspase do
Executes the cell
What are the two activation methods for apoptosis induction
Extrinsic Pathway and Intrinsic/Mitochondrial pathway
What regulates the intrinsic pathway
Pro- and anti- apoptotic signals from the Bcl2 superfamily
What are the 3 subfamilies of Bcl2 superfamily
- anti-apoptotic Bcl2 family
- pro-apoptotic effector Bcl2 family
- pro-apoptotic BH3-only
What does anti-apoptotic Bcl2 family do
Inhibit the pro-apoptotic Bcl proteins by binding to them and preventing the aggregation and forming of channels in the outer mitochondrial membrane
does NOT want the cell to undergo apoptosis
What does pro-apoptotic Bcl2 family do
Aggregate in the mitochondrial outer membrane to form channels that allow cytochromes C to exit through
WANTS the cell to undergo apoptosis
What does BH3-only family do
Inhibit the anti-Bcl2 family by binding so it can’t pro-apoptotic Bcl2 proteins
WANTS the cell to undergo apoptosis
What does DNA damage activate
The intrinsic pathway
