which organel is responsible for death in the cell

[arauca]

I have a vague understanding that Mitochondria in stress causes death in the cell . But our body is a collection of colony of cells , then the particular colony
have to come under stress, and Mitochondria will cause death of that colony , then the colony will cause death of the whole body.

 

[Asguard]

ok as i have been taught its not actually any organell which causes cell death, its the Na+\K+ pump. This is an active pump which requires ATP to run. Once that fails Sodium (Na) builds up in the cell and water follows through osmotic pressure this causes the cells to swell behond the ability of the plazma membrane to handle which causes the cells to burst.

There maybe other ways to kill a cell but this is the one we have been taught

 

[arauca]

ok as i have been taught its not actually any organell which causes cell death, its the Na+\K+ pump. This is an active pump which requires ATP to run. Once that fails Sodium (Na) builds up in the cell and water follows through osmotic pressure this causes the cells to swell behond the ability of the plazma membrane to handle which causes the cells to burst.

There maybe other ways to kill a cell but this is the one we have been taught

I appreciate your input

 

[arfa brane]

There is also the fact that most of the cells in a multicellular organism die off and are replaced, this is how an embryo develops, for instance. The process of prearranged cell death is called apoptosis, and it doesn't involve just one kind of organelle, but many.

A cell initiates intracellular apoptotic signaling in response to a stress, which may bring about cell suicide. The binding of nuclear receptors by glucocorticoids,[14] heat,[14] radiation,[14] nutrient deprivation,[14] viral infection,[14] hypoxia[14] and increased intracellular calcium concentration,[15] for example, by damage to the membrane, can all trigger the release of intracellular apoptotic signals by a damaged cell. A number of cellular components, such as poly ADP ribose polymerase, may also help regulate apoptosis.[16]

--http://en.wikipedia.org/wiki/Apoptosis

 

[arauca]

There is also the fact that most of the cells in a multicellular organism die off and are replaced, this is how an embryo develops, for instance. The process of prearranged cell death is called apoptosis, and it doesn't involve just one kind of organelle, but many.
--http://en.wikipedia.org/wiki/Apoptosis

Is it not that at the end Mitochondria release the toxic material that the cell go through apoptosis.

 

[Pete]

I think the key players in programmed cell death (apoptosis) are enzymes called caspases, not any particular organelle.

Substances released by mitochondria are part of some cell death pathways. It's not the final step.

 

[Techne]

There are quite a few ways in which cells die and quite a few organelles involved.

For apoptosis you have extrinsic pathways mediated by death receptors (e.g. DR5) and caspase 8 as well as others (wgich can activate the intrinsic pathway via tBid). In the intrinsic pathways you have mitochondria and the endoplasmic reticulum.

For macroautophagy you have autolysosomes that play a role.

Asgaurd I think describes a few aspects of necrosis.

The mitochondria is pretty well known. The mitochondria can become "leaky" or "depolarized" due to up-regulated bax activity (among many other BH3-related proteins. This causes cytochrome c to be released (among other pro-apoptotic proteins e.g. EndoG) which activates the apoptosome which in turn activates caspase 9 which in turn activates the executioner caspase 3. Caspase 3 cleaves proteins and causes DNA fragmentation etc.

Check out this nice animation to visualize the process:
http://www.youtube.com/watch?v=9KTDz-ZisZ0

 

[Hercules Rockefeller]

I have a vague understanding that Mitochondria in stress causes death in the cell.

Cell death can broadly be grouped into two types: necrotic cell death (NCD) and programmed cell death (PCD). Apoptosis is one well-known example of PCD.

NCD results from physical damage or adverse environmental conditions that the cell cannot repair or recover from. PCD can occur in response to a variety of factors, such as viral infection, unprepared mutations, developmental stage etc.

One of the apoptotic pathways is mediated by mitochondria. In other words, in response to certain stimuli, mitochondria will release pro-apoptotic factors (eg, cytochrome c) that will initiate the apoptosis pathway.

But our body is a collection of colony of cells , then the particular colony have to come under stress, and Mitochondria will cause death of that colony , then the colony will cause death of the whole body.

Not necessarily. There are always cells undergoing PCD in your body at any given time; this does not result in your death.