What is necrosis?
a passive, pathological process induced by acute injury or disease.
Cells that die by necrosis-
increase in volume and lyse (release their intracellular contents)
In necrosis, cytokines are-
released to neighboring cells
What is apoptosis?
an active, normal, physiological process that removes cells
What makes apoptosis different from necrosis?
it removes cells without damaging neighboring cells, or inducing inflammation.
Cells undergoing apoptosis have a __________ appearance of their membranes
blebbed
A disturbance in apoptosis can result in-
cancers, autoimmune diseases, and neurodegenerative disorders.
What is released that tells the cell to kill itself?
cytochrome c
What does phosphatidylserine do when the cell is undergoing apoptosis?
inverts and becomes exposed on the cells surface
How is a apoptotic cell removed?
by phagocytic cell, macrophages, and dendritic cells
What is the sequence in which a macrophage removes an apoptotic cell?
it is internalized, then degraded to reduce the risk of inflammation from the cell death.
Necrosis occurs over __________, while Apoptosis occurs in __________
several days, a few hours
What cytokines does the macrophage release that allows the inhibition of inflammation?
cytokines, IL-10 and TGF-B
What is replicative senescence?
the limited replicative span of cells, depends on the number of cell divisions and cell type
Accumalation of ________ can cause DNA damage and oxidative stress.
reactive oxygen species (ROS)
What are the triggers of senescence?
DNA damage, oncogene activation, telomere attrition, and ROS
What distinguishes senescent cells from quiescent cells?
they are incapable of replication, viable and metabolically active, resist apoptosis, express SA-B-gal
What is the cause of mitochondrial DNA mutations? and why is there a decrease in cellular oxidative phosphorylation activity?
- Oxidative stress by ROS.
- mutations to mtDNA accumulate due to the vulnerability of mtDNA to ROS which affects its function.
What is CRISPR?
genetically modifies genes