Apoptosis By Syeda Nida Zaidi

About 100 trillion cells are present in our body.

For every cell, there is a time to live and a time to die.

So, there are two ways in which cell die :

* Killed by *

Induced to injurious agents

commit suicide i.e. (NECROSIS) i.e.

(APOPTOSIS)

General definition.

So Apoptosis is,“ The process of programmed

cell death (PCD) that may occur in multicellular

organisms. Biochemical events lead to characteristic cell

changes (morphology) and death.”

Etymology and History

Apoptosis is a simple transliteration of Greek apoptosis "falling off" from apoptein "to fall off.

German scientist  Carl Vogt  was first to describe the principle of apoptosis in 1842.

Steps of Apoptosis :

Initiation Execution Phagocytosis

Initiation DNA

ATM

P53

BAX

Cytochrome CAPAFPro Caspase 9

Caspase 9

Intr

insic

Path

way

mitochondrion

Inhibiting domain hydrolysed

Protein breakdown starts

Casp

ase

Casc

ade

Execution

Cleavage of DNA

Cleavage of Cytoskeleton

DNase Inhibitor

Caspase 3

DNase

DNA

Bleb formation

Cytoskeleton network inside cell

Exe

cuti

on

Caspase 3

Phag

ocy

tosi

sBleb

Phagocyte

Engulfment of bleb

Phagocytes contain enzymes that finally metabolizes the bleb and its contents