Apoptosis Flashcards
IN GENERAL apoptosis is…
Programmed cell death
What two aspects are a part of apoptosis?
- physiological
- pathological
What are the two times in which you would commonly see physiological apoptosis?
- during embryonic development
- during immune system development
What are the two categories of pathological apoptosis
- triggered by immune system cells in response to cell infection
- self induced due to defective function
IN GENERAL what is necrosis
Morphological changes during cell death after lethal damage
-staged cell death due to unintended damage
Is necrosis pathological of physiological?
Always pathological
Apoptosis during embryonic development
Removing unwanted cells
-example: removing tissue from webbing between fingers and toes
Apoptosis during immune system development
- t lymphocytes are tested against “self antigen So” and if they recognize and bind self antigens, they undergo apoptosis to prevent damage down the road where they could kill normal cells
- help prevent autoimmunity disorders
Apoptosis triggered by immune system cells
-when a harmful cell is identified, innate immune cells trigger that cells death
What are the ways in which a damage cell can be identified
- infected cells display “non self antigens” on their surface
- cancer cells display weird attributes to be recognized
- damage cells develop characteristics of damage
Self induced apoptosis
- cell surpasses threshold acceptable for survival
- usually caused by metabolic defects of accumulating toxins or problem with mitochondria
Intrinsic apoptotic pathway
Initiated by interior signaling due to irreparable irreversible DNA damage
Extrinsic apoptotic pathway
Initiated by exterior signals due to indications of damage or infection
Who initiates intrinsic apoptotic pathways?
Pro-apoptotic proteins from the nucleolus and mito
Who initiates extrinsic apoptosis?
T-cells of TNFalpha induce the death domain proteins
What do extrinsic and intrinsic apoptosis have in common?
They both are caspase dependent
-different things activate caspases, but they are activated
What do cells do when caspases destroy proteins in the cell?
They begin to bleb into vesicles
What digests blebbed vesicles?
Phagocytic cells
AIF apoptosis inducing factor
A caspase-independent form of apoptosis
What does AIF do?
Leave the mitochondria goes through the cytosol, to the nucleus, to cause chromosome condensation
Once the chromosome is condensed by AIF, what happens to the DNA?
The DNA is chopped up
What is the over all effect of AIF?
The complete depletion of energy stores
- no new production of new proteins
- cell blebbing
- cell death WITHOUT USE OF CASPASES
What causes necrosis?
Severe trauma
What does necrosis involve?
- disruption of metabolic process
- cellular components denaturation
- loss of membrane integrity and release of cellular components
What does the disruption of metabolism leader told?
Loss of TCA and dependence on glycolysis
-leads to a build up lactic acid
What causes protein denaturation
Low ph from build up of lactic acid
Why is there an inflammatory response after necrosis?
Proteins are released from the cell into the tissue and causes inflammation
Why does cancer development
Continued inflammation stops cell death, so we’re cells don’t die, they reproduce and form cancer
Why is apoptosis good?
- considered a quiescent death
- does not negatively effect surrounding cells
- minimal repair/clean up needed
Why is necrosis bad?
- cause damage to surrounding cells
- extensive clean up needed
- lysosomes released cause hella problems
- inflammation leads to cancer
