BIO 1140 Lecture 9: BIO1140 Lecture 9
9 Feb 2017
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Document Summary
The size of organ or organisms depends on the total cell mass; the cell number must be controlled. Chemical messengers: growth factors, mitogen (cell division, survival factors. Necrosis: swelling (there"s a point where it can be reversed or not), then disintegration, this can lead to collateral damage. Apoptosis: condensation and break down the cell, then fragments of cells, phagocytosis, no leaking out of cell, no damaging neighbouring cells, does not occur only in response to negative stressors it is essential part of development. A stressor occur that a membrane cannot handle. When to high of calcium levels calpain activate. Calpain is a calcium dependant protease it de. Intracellular calcium levels rises degrades the lysosome membrane and it starts to attack the lysosome which has digestive enzyme. This leads to proteases (cathepsin) to be released (they like to eat proteins in the cells). Membrane will rupture and wont have enough healthy structures to sustain cell.
