And these red lines are basically our disulfide bonds. So if we take this protein and place it into a solution that contains urea and betama captive ethanol, we're going to denature the structure and separate these two polypeptide chains. So we are going to have a mixture of the green individual chain and the blue individual chain. And notice that in this particular example, the blue one is greater than our green one. So the next step is step number two. So once we separate that structure, once we separate these polypeptide chains, once we have the mixture of these two different types of polypeptide chains, the next question is how do we purify our mixture and isolate these two polypeptide chains into different compartments, into different beakers, for example?