Discuss how a protein forms a quaternary structure

Answer 1

The fourth level of protein structure is called quaternary structure. Quaternary structure occurs when two or more polypeptide chains join together. This level of complexity is somewhat like putting two or three crumpled paper fans together. Not all proteins have a quaternary structure-only those made from more than one polypeptide chain. In addition to the quaternary structure, a nonprotein component called a prosthetic group must sometimes be positioned precisely within a protein for it to function. Prosthetic groups often contain minerals that are needed for the protein to carry out its purpose. Hemoglobin is an example of a protein with quaternary structure and prosthetic groups because it is made from four separate polypeptide chains, each of which contains an iron-containing prosthetic group called heme. Heme is the portion of hemoglobin that actually transports the oxygen and carbon dioxide gases in the blood.