Figure 4.
DNA replication occurs in the cell nucleus prior to division of the mother cell into two daughter cells. When proteins are needed by the cell, RNA polymerase binds to the DNA at a specific sequence position – the promoter. The polymerase opens up the DNA double helix and begins to transcribe the bases from one of the DNA strands to create an RNA strand. The RNA strand is released into the nucleoplasm where it is processed to remove introns and other short sequences to create messenger RNA (mRNA). The mRNA molecule is transported into the cytoplasm. Ribosomes attach to the mRNA strand and begin the process of translation, to synthesize a protein based on the base sequence of the mRNA. Once the completed chain of amino acids is released from the ribosome it will fold into a specific 3-D structure to form the mature protein. Source: http://nobelprize.org. Copyright: Nobel Web AB