Biomedical Engineering Reference
In-Depth Information
represent the 20 common amino acids, as well as one start (ATG) and three
stop (TAG, TAA and TGA) markers. Redundancies normally occur in the last
nucleotide of the three-letter alphabet.
During translation, amino acids are added to the growing protein sequence one at a time as the
ribosome moves from codon to codon along the mRNA. The starting point for translation is marked
by a start codon. At the end of the coding sequence, marked by a stop codon, the translation ends
and the protein is released by the ribosome. Before the protein is transported outside of the cell to
perform or promote a variety of tasks, it is usually modified by adding a sugar, for example, and it
takes on a characteristic folded three-dimensional form—the focus of proteomics research.
