Within the cell are specialized parts for the transport of materials, energy capture and release, protein building, waste disposal, information feedback, and even movement. In addition to these basic cellular functions common to all cells, most cells in multicellular organisms perform some special functions that others do not. The work of the cell is carried out by the many different types of molecules it assembles, mostly proteins. Protein molecules are long, usually folded chains made from 20 different kinds of amino-acid molecules. The function of each protein molecule depends on its specific sequence of amino acids.
Most cells function best within a narrow range of temperature and acidity.
Carbon, because of its small size and four available bonding electrons, can join to other carbon atoms in chains and rings to form large and complex molecules. The genetic information in DNA molecules provides instructions for assembling protein molecules. The code used is virtually the same for all life forms. Genes are segments of DNA molecules, which contain instructions for specific proteins. Gene mutation in a cell can result in uncontrolled cell division, called cancer.