Proteins do everything in the living cells providing many essential functions in the body. Our body needs dietary protein to supply amino acids for the growth and maintenance of our cells and tissues. Insufficient dietary quantities of even one amino acid can quickly limit the synthesis and lower the body levels of many essential proteins. Protein categorized by function are Enzymes, Hormones, Transport proteins, Immunoglobulins, Structural proteins, Storage proteins, Energy source and Osmotic force.