Protein would not exist without the proper combination of amino acids. Proteins are essential to life. Proteins provides the structure of all living things. Each organism, from the smallest microbe to the largest animal is composed of proteins. And in its various forms, it is protein that participates in the vital chemical processes that enable us to sustain life.
Proteins are essential for growth.
Enzymes, hormones and genes are also comprised of various proteins. It is plain to see why meeting our body's protein requirements is so important to good health. All of the particular amino acids must be present for protein to be complete. Amino acids may be linked together to form more than 50,000 different proteins and 20,000 known enzymes. Each type of protein is composed of different amino acids, each being tailored for a specific purpose and need, so they are not interchangeable.