It is the versatility of carbon that provides for the uniformity of chemicals and atomic proportions of the elements found in living organisms. From simple carbon backbones, living organism can manufacture a multitude of different substances needed to sustain life. It is the variation among this multitude of organic molecules from species to species and individual to individual that distinguishes one from another Our goal in biology is to be familiar with the structure and function of the macromolecules of living organisms. Before reviewing the structure of the major groups of compounds of living organisms, we need to look at the element, carbon , what a hydrocarbon is, and also study the molecules called functional groups, which bond to hydrocarbons, altering the chemical nature of the resulting compound. As you know, the chemical characteristics and bonds formed by an atom are determined by the atom's electrons.
Carbon is one of the elements that forms covalent bonds to become stable.
Carbon has a valence of 4 so each carbon atom makes 4 bonds . Carbon may make bonds with other carbon atoms forming chains, branching chains or rings of linked carbon atoms. Ring compounds are common in living organisms. Double and triple bonds alter the bonding angles and shape of the resulting molecule. The bonding of carbons to carbons is called the carbon skeleton.