question about protein structure?

Question

do all proteins have their own primary, secondary and tertiary structure?

Answer 1

Yes.

The primary protein structure refers to the order or sequence of amino acids in the protein chain.

The secondary protein structure refers to the arrangement of the amino acid chain into a long molecule.

The tertiary protein structure refers to the overall shape of the protein.

Answer 2

No. Forth one there and called, Quaternary. A great majority of the proteins are composed of single polypeptide chains. Some of the proteins, however consists of two or more polypeptides which may be identical or unrelated. Such proteins are termed as oligomers and possess quaternary structure. The individual polypeptide chains are known as monomers, protomers or subunits. A dimer consists of two polypeptides while a tetramer has four.

The monomeric subunits are held together by non-convalent bonds namely hydrogen bonds, hydrophobic interactions and ionic bonds.

Answer 3

http://chemistry.about.com/library/weekly/blprotein.htm
primary,secondary tertiary and quaternary structures exist.

There are four levels of structure found in polypeptides and proteins. The primary structure of a polypeptide of protein determines its secondary, tertiary, and quaternary structures.