Proteins are composed of carbon, hydrogen, oxygen, and nitrogen arranged in a variety of ways to form a large combination of amino acids. Unlike fat the body has no storage deposits of protein. All of it is contained in the body as important parts of tissues, blood hormones, and enzymes. The structural components of the body that contain these amino acids are continually undergoing a process of breakdown and replacement. The respiratory quotient for protein metabolism can be demonstrated by the chemical equation for oxidation of albumin: