Animation showing the denaturing of a protein by heat. Proteins are polymers made up of long chains of amino acids. The location of different amino acids on the chain helps to determine the structure of the protein. It folds into a specific three-dimensional shape due to interactions between the amino acids, and between other atoms, ions or molecules (such as metal ions or water). The biological activity of a protein is determined largely by its shape. The shape can be disrupted by numerous factors, such as heat, acids, alkalis and solvents. Here, heat (red) is seen to disrupt the structure entirely, a process called denaturing. This destroys the activity of the protein. See clips K004 3257 and 3258 for the protein in alkali and acid.