What is Carbon? Why is it in all organic matter and what function does it provide?

Carbon is the chemical element that makes up the "backbones" of all the long chains in carbohydrates and fats. It's also the commonest element in rings of atoms found in proteins and molecules like DNA. Typically, carbon atoms have hydrogens hanging off them.

The reason carbon is a suitable material for life is its flexibility in joining with other atoms. It normally can form four bonds, either with four different hydrogens, carbons or other elements or sometimes two double bonds or one double bond and two singles. The only other element with similar options is silicon and so some science fiction writers have imagined worlds where silicon is the basis of life.