Proteins have a variety of functions within a living cell. describe at least three of the possible functions of proteins, and explain how proteins can be so diverse when there are only limited number of different amino acids

Proteins serve as units of transportation, they are a source of energy and they build and maintain structures inside the body. there may be only 21 amino acids but you can arrange them in any way making for numerous amounts of proteins

Cells of an organism tell each other when predators are near.