tertiary structuremedical dictionary

<biochemistry, chemistry> The third level of structural organisation in a macromolecule.

The primary structure of a protein (for example) is the amino acid sequence, the secondary structure is the folding of the peptide chain (alpha helical or beta pleated), the tertiary structure is the way in which the helices or sheets are folded or arranged to give the three dimensional structure of the protein. Quaternary structure refers to the arrangement of protomers in a multimeric protein.

(13 Jan 1998)