Final answer:
A functional group is an arrangement of atoms found in macromolecules that imparts specific chemical properties to those molecules.
Step-by-step explanation:
A functional group is an arrangement of atoms found in a variety of macromolecules that imparts specific chemical properties to those molecules. Functional groups are found along the carbon backbone of macromolecules, which consists of chains and/or rings of carbon atoms with occasional substitutions of elements like nitrogen or oxygen. Each of the four types of macromolecules - proteins, lipids, carbohydrates, and nucleic acids - has its own characteristic set of functional groups that contribute to their different chemical properties and functions in living organisms.