3. Introduction
o Apoptosis, or programmed cell death, is a highly
order for the body to eliminate unwanted or
dysfunctional cells.
o During apoptosis, the genome of the cell will
fracture, the cell will shrink and part of the cell will
disintegrate into smaller apoptotic.
o Between 50 and 70 billion cells die each day due to
apoptosis in the average human adult. For an average
child between the ages of 8 and 14, approximately 20
billion to 30 billion cells die a day.
4.
5. Significance of apoptosis
Maintanance of normal tissue during
development
Remove of damaged cell
Prevent tumour formation
Condensation of chromatin
6.
7. Importance of apoptosis
◦ Programmed cell death is needed for
proper normal development
◦ Examples:
The moldiness of the tadpole tail in frog .
The formation of the fingers and toes of the
foetus requires the removal, by apoptosis.
The sloughing off of the endometrium at the
start of menstruation.
10. Extrinsic pathway
o Death receptor- cell surface receptor that transmit
apoptotic signals, initiated by specific ligands.
o Plays a central role in instructive apoptosis.
o Death receptor activates death caspases within seconds
of ligand binding, causing an apoptotic demise of the
cell within hours.
o Ligands fas ligand,tumor necrosis factors TNF alpha
and tumor necrosis TNF related apoptosis including
ligand trail .
11. Extrinsic pathway
(contd..)
o Caspases play the central role in the
transduction of death receptor apoptotic
signals.
o Caspases are proteins that are highly
conserved.
o Caspases 8 start to cleave other pro- caspases
to result active form of caspases.
o These caspases go to execution phase and
causing apoptosis.
12.
13.
14. Intrinsic pathway
o Known as mitochondrial pathway.
o Apoptosis occur due to increase permeability of
mitochondria.
o Radiation and other factors assist to remove these signal
e.g. Bcl-2Sand BclX via other type of pro apoptotic
proteins such as Bak, and Bax.
o Increasing the permeability of mitochondria resulting
leakage of pro apoptotic molecules from mitochondria to
cytoplasm.
15.
16.
17. Conclusion
Apoptosis is a fundamental biological
phenomenon of organisms.
The process of apoptosis is characterized
by morphological and biochemical
changes such as shrinkage of cell plasma,
condensation and disintegration of
chromatin into fragments and formation of
apototic bodies.
18. Reference
Ahmad, M., Srinivasula, S.M.,WANG, L., Talanian, ,R,V.,
Fernandes- Alnemri, t., E,S., 1997.CRADD,anovel humana
apoptotic adaptor molecule for caspase-2,and fasLtumor
necrosis factor-interacting
protein RIP. Cancer RES.57,615-619
