A cells is made up of over 5000 chemicals. The structure and function of different cell constituents are interplay of their constituent chemicals, their arrangement and properties. About 93% of the cellular material is build up of three non-mineral elements- carbon (17.5%), hydrogen (9.4%), and oxygen (66.6%). C, H, O and N are called the principal elements as they make up more than 95 % of the cellular structure. Minerals constitute 5% of the cellular materials. Metals which are present in major amount are calcium, potassium, sodium, magnesium and iron. The metals present in traces are cooper, zinc, manganese, molybdenum, cobalt and chromium. Non-metals include nitrogen, sulphur, phosphorus and chlorine majorly. In traces non-metals like boron, iodine, selenium, and fluorine are also present.
The chemicals of the cellular pool functions as raw materials for carrying out various biochemical reactions of the cell organelles and the cell. Low molecular weight, small sized micromolecules include water, gases, minerals, sugars, lipids, amino acids and nucleotides. Whereas higher molecular weight, large sized complex macromolecules are proteins, nucleic acid, and polysaccharides.