Normal solution for a liter of water solution in a solution containing one gram equivalent solute, refers to the concentration of 1N solution. The indicator indicator (Indicator) is affected by the existence of certain substances to change their color material. Mainly used for indicating the end point drop in volumetric analysis. In general can be divided into acid the indicator, redox indicator, indicator indicator. In addition to adsorption analysis, can also be used to test the gas or solution of some harmful toxic substances.
The old name for enzymes. With special catalytic ability of the protein. It consists of organisms (animal, plant, microorganism), or enzyme as a biological catalyst. It continues to promote a large number of complex chemical reactions in living organisms. Such as amylase starch and glycogen hydrolysis catalyst into dextrin and maltose; enzymatic protein hydrolysis peptide; lipase catalyzed hydrolysis of fats into fatty acids and glycerol.