When you remove it from your hand you will lose the shape of the protein. Wrap it around your hand in a helix (corkscrew) shape. This represents the primary structure of a protein. To learn more about protein structures (1В°, 2В°, 3В°, 4В°) see the chemBAM page. However, when the protein is denatured, the primary structure remains intact. If the interactions between chains are lost, due to a breaking of hydrogen bonds for example, we see a loss in the shape of the protein. These interactions are known as the tertiary structure. These can interact with each other causing the protein to fold even more and give it a 3D shape. We also need to consider the interactions between different side chains on the amino acids in the protein. In this diagram we see two protein chains stabilised by hydrogen bonds (in red), again between the amine of one amino acid and the acid of another. Beta sheet with magnified area showing hydrogen bonds between amino acids We refer to these as beta-sheets which form when hydrogen bonds form between two different protein chains. In this diagram of the alpha helix, we see hydrogen bonds (in red) holding together different sections of the protein chain, resulting in a spiral shape.ДЄnother thing we need to remember is that proteins donвЂ™t exist as single chains, we get lots of protein chains that can interact with each other. Alpha helix with magnified area showing hydrogen bonds between amino acids Hydrogen bonds form between the acid group of one amino acid, and the amine group of another. This is known as an alpha-helix as it gives the protein a corkscrew shape. Hydrogen bonds can then form between different segments of the chain, keeping these folds in place. This allows the protein to fold in on itself. The amino acids in the peptide chain can rotate around their bonds making the protein very flexible. This is made up by alpha helices and beta sheets. We also need to consider the secondary structure of a protein, which determines its shape. In real life, proteins arenвЂ™t just one really long straight chain. Try and rearrange the order of amino acids to form a different peptide chain. Remember the order of amino acids in the chain is very important for the properties of the protein. Now see if you can combine these three amino acids to form a peptide! If you can, think about why the bonds are forming at the specific atoms you have chosen Have a go at building some (very small) proteins! Try and work out which amino acids form from each of these amines and acids. The sequence of amino acids in the chain is known as the primary structure. It also tells your body which proteins to make depending on what you need. DNA stores genetic information, which basically means it tells the body everything about itself, like eye colour, hair colour or whether you have dimples or not. The order of the amino acids is determined by your DNA. As a result, the order of each of these in the chain can actually result in big changes in the properties of the protein itself. Proteins are made up of hundreds of thousands of these peptide-bonded amino acids in long chains! There are twenty possible amino acids in proteins, each with different side chains that provide different properties. Reaction scheme showing the formation of a peptide from two amino acids When two amino acids join together they form a peptide, named after the bond that forms between them. There are many different types of amino acid (this one above is called glycine) and they can combine in many possible ways to form tons of different proteins. Reaction scheme showing the formation of amino acids from amine and acids These are often referred to as the fundamental вЂbuilding blocksвЂ™ of all proteins. Proteins are made up of long chains of molecules called amino acids, named like this because they are made up of amines and acids.

Building blocks of proteins