The amino acids are linked covalently by peptide bonds. The graphic on the right shows how three amino acids are linked by peptide bonds into a tripeptide.
The schematic below shows the N-terminal at the upper left and the C-terminal at the lower right.
The sequence of amino acids in a polypeptide is dictated by the codons in the messenger RNA (mRNA) molecules from which the polypeptide was translated. The sequence of codons in the mRNA was, in turn, dictated by the sequence of codons in the DNA from which the mRNA was transcribed.
Proteins are made up of one or more polypeptide molecules. Follow these links to examine the various levels of polypeptide organization in proteins.
|Primary structure||Secondary structure||Tertiary structure||Quaternary structure|
3 March 2011