Biochemistry, Tertiary Protein Structure

Nearly every function in living beings depends on proteins. They account for 50% of the dry mass of cells and play a role in everything an organism does. There are many different types of proteins. Different proteins can play a role in speeding up chemical reactions, storage, defense, cell communication, movement, and structural support. A human has tens of thousands of proteins in their body at any given moment in time. Each of these proteins has its structure and function. They are known as the most structurally complicated biological molecules. As diverse as they can be, they are all made up of the same 20 amino acids. By forming peptide bonds between the amino and carboxyl groups on two different amino acids, large polypeptide chains can be created. Every protein can be described according to its primary structure, secondary structure, tertiary structure, and quaternary structure is present. In brief, primary structure is the linear chain of amino acids. Secondary structure is comprised of regions stabilized by hydrogen bonds between atoms in the polypeptide backbone. Tertiary structure is the three-dimensional shape of the protein determined by regions stabilized by interactions between the side chains. Quaternary structure is the association between two or more polypeptides, but not every protein has a quaternary structure.