Cell division is an important process in the human body. Regeneration resulting from cell division, along with the programmed death of old cells, or apoptosis, allows the body to grow, change, and repair itself. Apoptosis also eliminates abnormal, inefficient cell structures, and maintains basic, healthy biological functions, including proper immune response.
Just before division, a parent cell's DNA is fed through a replication bank. A complex protein called helicase unwinds each ladder section of the molecule and breaks the hydrogen bonds between the bases comprising the rungs to create two separate strands. A specialized enzyme then creates something akin to a template on the opposite side of each separated strand. With the template in place, a replication enzyme builds a new strand of DNA—complete with the damage, if any, contained in the original strand. Finally, the section seals and twist back into its characteristic helical pattern. Section by section, the proteins move down the structure, creating two separate, identical molecules of DNA.