MCD BIO 165A Lecture Notes - Lecture 17: Programmed Cell Death, Cytochrome C, Flippase
15 Dec 2016
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Programmed cell death: one of several ways to die, necrosis. Trigger can be internal or external: cell does not leak components of itself into the outside environment so there isn"t inflammation, both are happening at all time. Apoptosis: cell dehydration -> shrink -> change in cytoskeleton -> cell blebbing, chromatin condensation, nuclear fragmentation, membrane integrity preserved, apoptotic bodies - small trunk cells, contents are never released to outside, macrophages will remove these. Necrosis: cell and mito swelling, plasma membrane ruptures, this cause damage to normal tissue b/c of lysosomal enzyme leakage. In heart, cardiomyoctes undergo damage and healthy neighbors are damaged: this tissue cannot regenerate. Middle: apoptotic cell: cell loses water - membrane cannot control influx/efflux -> shrinkage, mito breaks down as a result. Pi serine flipped to outer leaflet -> macrophages recognize this. Needed for morphogenesis, development of digits, formation of lumen. When you don"t need these b cells, they are eliminated thru apoptosis.
