Amino acids are the basic structural building blocks of the protein. Proteins are the necessary part of every living cell in the body that make the greatest portion of our body weight.Since the proteins that make our body are not directly obtained from the diet because dietary protein is broken down into amino acids. In the body these amino acids either rebuild into a specific protein which the body required or may perform other function within the body. Thus it is the amino acids not the protein that are required as an essential nutrients.( Read Amino Acid More Info..)