Readers learn that a living organism is a system, or structure, that reproduces, changes with its environment over a period of time, and maintains its individuality by continuous metabolism. To maintain life, an organism repairs or replaces (or both) its structures by a constant supply of the materials of which it is formed. It keeps its life processes in operation by a steady supply of energy. A major contributing part of an organism's survival is the functioning of its cells. This volume provides essential information on cell functions, including amino acids, fibrous and globular proteins, DNA, protein synthesis, and metabolism.