The law of conservation of mass or principle of mass conservation states that for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as the system's mass cannot change, so the quantity can neither be added nor be removed.
Essential amino acids Amino acids are the molecules that make up proteins when they are linked up. There are certain essential amino acids, namely they are <span>histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. All of these must be obtained from one's diet. If they are not, the body will use existing proteins, such as muscle mass, to obtain them.</span>