The primary structure of a protein is made up of a sequence of amino acids which is coded for by the organisms DNA triplets which are transcribed in the process of protein synthesis, the secondary structure of the enzyme is then formed by hydrogen bonding between molecules from the amino acids - the most common two forms are alpha helices or beta pleated sheets. The tertiary structure involves more bending and folding with ionic bonds between charged molecules and disulphide bridges between the amino acids cysteine - this forms a specific tertiary structure also know as an active sight - in enzyme controlled reactions the shape of the tertiary structure is complementary to that of the substrate allowing the reaction to take place