The iceberg that sank Titanic would have been up to a mile long, displacing around a billion tonnes of seawater. It would have taken the iceberg over a year to edge its way down the 40-mile fjord.
Chapters 1 and 2 introduced a-helices and b-sheets (Secondary Struture), and some common motifs composed of 2 or 3 of these elements (Super-secondary Struture). Tertiary structure describes the folding of the polypeptide chain to assemble the different secondary structure elements in a particular arrangement.As helices and sheets are units of secondary structure, so the domain is the unit of tertiary structure.In multi-domain proteins, tertiary structure includes the arrangement of domains relative to each other as well as that of the chain within each domain.There is a blurred distinction between super-secondary structure and tertiary structure.lthough the term motif is often used to describe super-secondary structures (e.g. Branden and Tooze, 1991), it may also be used to describe a consensus sequence of amino acids identified in a number of different proteins, rather than a repeated three-dimensional conformation.
In biochemistry and molecular biology, the tertiary structure of a protein or any other macromolecule is its three-dimensional structure, as defined by the atomic coordinates. Proteins and nucleic acids are capable of diverse functions ranging from molecular recognition to catalysis.he structure of these molecules is frequently decomposed into primary structure, secondary structure, tertiary structure, and quaternary structure. The scaffold for this structure is provided by secondary structural elements that are hydrogen bonds within the molecule.