Functional groups 1) Functional groups are clusters of atoms with characteristic structure and functions 2) Most biomolecules contain more than one functional group 3) Different families of organic compounds result when hydrogen atoms on organic molecules are replaced by different functional groups 4)The distinct chemical properties of each functional group contribute to the behavior of any molecule that contains it1) Functional groups are clusters of atoms with characteristic structure and functions. 2) Most biomolecules contain more than one functional group. 3) Different families of organic compounds result when hydrogen atoms on organic molecules are replaced by different functional groups. 4) The distinct chemical properties of each functional group contribute to the behavior of any molecule that contains it. Functional groups