Cell death Flashcards
TRUE or FALSE: Critical for normal physiology
* Embryogenesis
* Tissue homeostasis
true
When is a cell considered dead?
- when membrane integrity is lost
- when it and its nucleus have undergone complete fragmentation
- when its corpse or fragments have been engulfed by another cell
Autophagic cell death occurs during autophagy where ??? material within autophagolysosomes takes place
sequestration of cytoplasmic
what type of cell death often promotes cell survival?
autophagic cell death
what type of cell death is when there is swelling and rupture of injured cells but they are lacking features of apoptosis or autophagy
Necrosis
the following are morpholopgical features of apoptosis or necrosis?
- Rounding-up of the cell
- Retraction of pseudopodes
- Reduction of cellular and nuclear volume
- Nuclear fragmentation
- Minor modification of cytoplasmic organelles
apoptosis
*Bcl-2 family protein activation
*Caspase activation
*Reactive oxygen species overgeneration
*Decreased mitochondrial
membrane potential
*DNA fragmentation
*ssDNA accumulation
are biochemical features of apoptosis or necrosis?
apoptosis
*Cytoplasmic swelling (oncosis)
*Rupture of plasma membrane
*Swelling of cytoplasmic organelles
*Moderate chromatin condensation
are features of apoptosis or necrosis?
necrosis
- Calpain and cathepsin activation
- Decreased ATP levels
- HMGB-1 release
- Plasma membrane rupture
- RIP1 phosphorylation and ubiquitination
- ROS overgeneration
are biochemical features of apoptosis or necrosis?
necrosis
*Lack of chromatin condensation
*Massive vacuolisation of cytoplasm
*Accumulation of autophagic vacuoles
* Little or no uptake by phagocytic cells, in vivo
are morphological features of necrosis, or autophagic cell death?
autophagic cell death
- Beclin-1 dissociation from Bcl-2/XL
- Dependency on atg gene products
- LC3-I to LC3-II conversion
- p62Lck degradation
are biochemical features of necrosis or autophagic cell death?
autophagic cell death
events in apoptosis include:
- membrane blebbing
- ??? compaction
- nuclear fragmentation
- cell fragmentation
Chromatin
Pyknosis = irreversible condensation of chromatin.
e.g ???
loss of tissue between developing digits
Phosphatidylserine normally resides in inner leaflet of the plasma membrane but flips to the outer leaflet during ??? which assists in the binding and phagocytosis of dying cells
apoptosis
