Apoptosis Living organisms are truly fascinating not only for the ways they function within their larger environments, but also at the microscopic level in how they function in and of themselves. Ultimately, of course, these two views and understandings of organisms are wholly linked and entirely inseparable, as no organism would be able to function in the environment at large if it was not functioning properly at the microscopic level. Without muscle fibers properly contracting and expanding, it would be impossible for the human fingers to type away on a keyboard; without the proper nerve cells being triggered and the right neurons firing in the brain, a shark would be unable to smell, detect, and go after its prey; if blood cells were not permeable to the right substances in the right amounts, nutrients and necessary molecules couldn't be transported throughout the body as they were needed.

All of this points out a fairly obvious biological fact: cells are the basic unit of functionality in any organism. The lives of cells are thus very important to the lives of organisms, but their deaths are somewhat less appreciated. Apoptosis, which is programmed cell death, is essential to most organisms for a variety of reasons, and can be though of as "nature's sculptor," carefully removing any material that is not necessary so that the work of art that is the living organism...

At times, apoptosis can also occur when it is not supposed to, and this (as might be imagined) can lead to significant health issues (DHHS 2005). The mechanisms by which apoptosis occurs, its usefulness to the body, and its potential harm will be discussed below.
There are essentially two ways in which cells die -- they are either "killed" or "commit suicide" (Kimball 2011). "Killed" cells are injured by something external -- torn skin or toxin-exposed organ tissue, for example; apoptosis refer to cells that "commit suicide," or use natural body processes to result in their own death (Kimball 2011). When a cell receives information that it should die, either due to internal damage or genetically-encoded information, the mitochondria in the cell exhibit a specific protein that inhibits the production of another marker protein and apparently acts as a signal for the cell to undergo apoptosis (Kimball 2011; Dash 2011). The internal components of the cell essentially break down, with the nucleus often becoming "horseshoe shaped" and the entire cell shrinking down and becoming far more compact, to assist in a macrophage's disposal of the cell (Dash 2011).

There are a variety of reasons why a cell would want to "commit suicide." Bodies change as they go through different stages of a life…