How are proteins made?To make a protein, a cell must put a chain of amino acids together in the right order. First, it makes a copy of the relevant DNA instruction in the cell nucleus, and takes it into the cytoplasm - a bit like taking a photocopy of the instruction manual from the manager's office out to the assembly lines in a car factory. Here, the cell decodes the instruction and makes many copies of the protein, which fold into shape as they are produced.
How is a DNA instruction copied?
The first part of the DNA double helix in the cell nucleus unwinds and unzips. The DNA instruction is revealed, flanked by 'start' and 'stop' codes. The cell makes a copy of the DNA in the form of an RNA molecule. The RNA copy is trimmed, and then enters the cell cytoplasm to be decoded. It is now called messenger RNA (mRNA).