We have the secondary structure which are basically these regular patterns that are formed so alpha, helixes, beta sheets, beta turns and omega loops. We have our tertiary structure which basically consists of these amino acids that are far away from one another and they interact with one another to give that tertiary structure. And finally, we also have those proteins that contain a fourth level quadinary structure. This means that protein consists of two or more polypeptide chains. Now, not all proteins will contain quarterly structure. For example, an important type of protein in our muscle is myoglobin.