So if we're in a very basic solution, let's say a solution with a PH of ten, all of our cysteine molecules will predominate, will exist in this ion form, and this will be able to form ionic bonds with positively charged species. Now, lying, tyrosine and arginine have a very basic PKA value. It's above ten. For lycine, it's 10.8, for tyrosine, it's 10.9, and for arginine, it's all the way at 12.5. And what that means is, at the normal physiological PH, these three amino acids will always exist in this form. In the tyrosine case, we have a neutral, non polar sidechain group.