The native structure describes the biologically active structure of our enzyme. Now, the next question is, what did he actually want to do with these different molecules? Well, the plan was to destroy the tertiary and the secondary structures of the ribonuclease by using these appropriate agents and then to see under which conditions did the native structure of that ribonuclease basically reform. So now let's take a look at these three experiments. Let's begin with experiment number one. In experiment number one, he took that active ribonuclease enzyme that contains this secondary and tertiary structure and he placed it, he mixed it with an excess amount of Beter Mcaptoethanol and a large amount of urea.