Carbon is an element that has unique properties that allow it to form covalent bonds with other elements. These bonds are important in the formation of cells and are crucial to the function of respiration and energy creation, making it one of the most vital elements of life.
In terms of respiration and food metabolism, carbon is vital in that it combines with oxygen and glucose in mammals in order to produce carbon dioxide, water and energy (in the form of heat). Although mammals do not require the carbon dioxide and release it into the atmosphere, plants use it in order to photosynthesize, making use of it in the opposite manner of mammals.
Cells are made of a series of complex molecules known as macromolecules. These include proteins, nucleic acids, carbohydrates and lipids. These are all subsets of organic molecules, which are molecules that contain carbon. Because carbon is present in these molecules, this in turn makes carbon vital to life.
The ability of carbon to form covalent bonds makes it versatile. Considered a basic structural component, carbon is known as the backbone of macromolecules and one of the building blocks of life. It is the fourth most abundant element on earth.