And that will drive the energy of the CIS configuration to be higher than that of the trans configuration. And so in the majority of cases, we only really see the trans peptide bonds and never the cyst configuration bonds because of this idea that this creates a more stable system that is lower in energy. Now, I say in the majority of cases because actually in some cases we do see the CIS configuration, but we'll discuss that in much more detail in future electros. So from this discussion we saw that because we have these peptide bonds that have double bond character, there is no rotation about the atoms between our peptide bonds. Now, the question is the following. Notice we have a linear polymer of amino acids, but the final three dimensional structure proteins is not a linear structure, it's a convoluted structure.