Apoptosis Flashcards
What are the two paths of cell death called?
Necrosis and Apoptosis
Which of the two cell death pathways is unexpected
Necrosis
In necrosis, what is the impact of losing the ATPase activity?
Loss of the electro chemical gradient, and a huge lack of atp
Since ATP is no longer there after the atpase in lost in necrosis, what are the impacts of that?
Cellular functions no longer work, but esp. the water pumps are no longer working, causing the water that is pouring in to not be able to leave.
Why is necrosis sometimes harmful to neighbouring cells?
enzymes contained in the cell are now spued into the environment, enzymes that can seriously damage other cells.
What is the impact of all the water entering the necrotic cell?
the cell swells up til it bursts
What can trigger necrosis?
Physical damage, disrupted blood supply, and ischemia
what are two different kinds of apoptosis?
Intrinsic and extrinsic
what are several ways that apoptosis can happen?
Loss of a survival factor, damaged DNA
Where does the order for intrinsic apoptosis come from?
it is encoded in the cells own dna
What does the original trigger in apoptosis activate?
Bad (pro-apoptotic)
what does Bad inhibit, and what does it activate?
inhibits BCl2 and activates Bax and Bak
What are the two types of caspases?
Initiators and executioners
What do caspase initiators do?
Activate other destructive enzymes such as DNAase
what do executioner caspases do?
Disrupt cell adhesion, disassemble the nuclear envelope, and change the cells shape and size
What do Bax and Bac do?
initiate the mitochondria to release calcium, which open the permeability transition pore, which allows Cytochrome C to be released
What is Cytochrome C?
They are molecules (from the mitochondria) that initiate the building of apoptosomes in the cytosol,
What can apoptosomes do?
they can initiate caspase cascades
Define blebbing
small vesicles pinch off from the original apoptotic cell
What is the macromolecule called that flips phosphatidalserine to the outside of the blebs?
scramblase, a flipase
What is the power source of scramblase
the extra calcium concentration present from what happened in the cell with the mitochondria letting all the calcium go
What is mitophagy
The regulation of how many mitochondria are in a cell
What two enzymes are responsible for cutting a mitochondria
F1S1 and DRP-1
what happens to the healthy part of a mitochondria
It is moved to merge with another part of a healthy mitochondria
What does the apoptosome do?
It is responsible for initiating caspase cascades
Why do cells undergo apoptosis?
They have outlived their purpose, they are not needed in the adult version of the organism
What is DNA laddering?
The fragmentation of DNA into pieces during apoptosis, seen when placed in a gel and the pieces are observed to spread apart
What does Bad inhibit?
BCL2
what causes blebbing?
The localized uncoupling of the cytoskeleton from the plasma membrane
