Biochemists concentrate such things as the structures and physical properties of biological particles, including proteins, sugars, lipids, and nucleic acids; the components of catalyst activity; the compound control of digestion; the science of sustenance; the sub-atomic premise of hereditary qualities (legacy); the science of vitamins; vitality usage in the cell; and the science of the insusceptible reaction. The science of biochemistry has also been called physiological chemistry and biological chemistry.