Answer:
Matter
Explanation:
Matter refers to the atoms, molecules, compounds which we are composed of and our surrounding is made of.
The law of conservation of mass was proposed by the Antoine Lavoisier who stated that mass neither gained nor lost but changed its form from one form to another in his experiments.
The same law of conservation of mass applies to the biological organisms as like living things they are also made up of the matter. The metabolism of the chemical reaction taking place in the living organism is evidence of the law of conservation of mass.
Thus, the matter is correct.
Although amino acids may have other formulas, those in protein invariably have the general formula RCH(NH2)COOH, where C is carbon, H is hydrogen, N is nitrogen, O is oxygen, and R is a group, varying in composition and structure, called a side chain.
Cellular respiration occurs in the mitochondria
