What is a function if a protein?

Proteins are vital components of our bodies. They form part of the body's structure and perform many essential functions, such as allowing us to move, distributing oxygen around the body, clotting blood when we're wounded, fighting infections, transporting substances into and out of cells, controlling chemical reactions, and carrying messages from one part of the body to another.

They do most the work in the body regarding structuring and rebuilding muscles tissues and organs.