PETROLEUM CHEMISTRY Carbon is so Important in the Life Cycle. It has numerous ways of bonding with many other elements, particularly oxygen and hydrogen. It can form both “organic” and “inorganic” compounds. Organic compounds are considered unstable in the biosphere because they are in the reduced state. Whereas Inorganic compounds, principally calcite (CaCO3 ) and dolomite (CaMg(CO3 )2 ), are stable because they are in the oxidized state. Carbon is present in most substances that are vital for the development of life (called “biomolecules”): Proteins, lipids, sacharides, etc