I need a argument to: Differences in the structure of protein molecules affect how they connect to other protein molecules. This can result in different traits

Protein is an important part of a healthy diet. Proteins are made up of chemical 'building blocks' called amino acids. Your body uses amino acids to build and repair muscles and bones and to make hormones and enzymes. They can also be used as an energy source.

Element: A chemical material that forms of a special type  of atom and can not be broken down by a chemical  reation or transformed. 

Substance: A type of matter with a constant chemical composition and properties that are characteristic. It is  composed of one form of molecule or atom.