there are four main classes
carbohidrates -built from small molecular units that are connected to each other by a strong covelent bonds.
lipids-lipids are molecules that contain hydrocarbons and make up the building blocks of the structure and functions of living cells
protiens -built from small molecular units that are connected to each other by a strong covelent bonds.
nucleic acids -built from small molecular units that are connected to each other by a strong covelent bonds.
