Carbon is the basis for all life on Earth. Carbon is abundant on Earth. It easily bonds with oxygen, nitrogen and hydrogen. Carbon bonds easily because of its four valence electrons. It is capable of bonding with itself in long chains. Astrobiology asserts that if life is found elsewhere in the universe it will be carbon based. Scientists who disagree with this view call it carbon chauvinism.
The chemicals which are necessary for life are all based on carbon compounds. They consists of proteins, nucleic acids, carbohydrates and lipids.
Proteins are the foundations of living structures.
The nucleic acids which contain genetic information.
Carbohydrates which store energy.
Lipids which also store energy.