The theme "form=function" represents the shape of the biomolecule that determines its function.
The theme "form=function" can be best understood by the study of proteins. Proteins are the biopolymer made up of the repeting subunits of monomers called the amino acids. Amino acids are the organic compounds made up of an amino group and a carboxyl group. In addition to this, they contain a functional "R-group" that determines the amino acid. These R-groups in the amino acids of a protein either attract or repel from each other giving a three dimensional structure to the protein which is critically important for its functioning.
Similarly, the cell wall of the plants are made up of the cellulose. It is a structural carbohydrate biomolecule responsible for providing rigidity to the cells and protecting them.
