New goods and products are continually being manufactured from raw materials. In cities this takes place in workshops and factories. Raw materials are transformed, usually in a sequence of steps on a production line, into finished products. The process is governed by a clear set of instructions or specifications. In some cases the final products are for immediate or local use, in others they are packaged for export.
In the
cell too there are production lines, in this case manufacturing new proteins of many
different sorts. The messages from the cell's DNA act as a
blueprint. This blueprint is interpreted by machines on a production line, which are
called ribosomes, to assemble the correct sequence of amino acids. Amino acids are the
building blocks used to make proteins. As in cities where products made in factories are
used within the city, so the completed proteins are often for home consumption, but others
may be exported outside the cell for use elsewhere. All manufacturing creates waste products, which need to be disposed of.
