Answer:
The molecular structure of complex macromolecules show that a chemical reaction has occurred.
Step-by-step explanation:
A macromolecule is defined as molecule containing a very large number of atoms, such as a protein, nucleic acid, or synthetic polymer.
Macromolecules are formed by chemical reactions between simple molecules which join together to give the macromolecule.
If we look at the structure of a macromolecule very closely, we will discover evidences that show that the complex structure of the macromolecule was created by stepwise chemical reactions.