If a cell fails to die when its utility is over, it is likely to multiply rabidly and form a cancer. Conversely, a person who has too many prematurely self-destructing cells may develop degenerative diseases like Alzheimer's.

Researchers led by Ruth Kluck at Melbourne's Walter and Eliza Hall Institute have identified a key step in the mechanism by which cells self destruct, one that could have far reaching implications for medicine.

Findings of the study have been published in the latest issue of the journal Molecular Cell.

The process is called 'apoptosis', wherein certain proteins cause the cell to dies by puncturing its 'power plant'.

Kluck and her colleagues have discovered how they do this - an important step towards the identification of targets for drugs designed to regulate cell death.

The protein that drives this self-destruction is called Bak. It acts by puncturing the membrane of mitochondria - the cell's power plant and cause it to die.

Properly regulated cell death is actually essential for good health. This is because our cells naturally have a limited life span, reports Sciencealert.

Worn out, damaged or unnecessary cells are eliminated at the rate of a million per second and replaced by the same number of new cells for as long as we live.