Serine? So last century. Valine? Over it. Glycine? You’ve got to be kidding me.

Those chemicals are part of the 20 amino acids that are typically incorporated into proteins. That means they have a dedicated place in what’s called the genetic code, which translates between the bases of DNA to the amino acids of proteins.

Granted, the genetic code has enabled the entire diversity and complexity of life on Earth, from E. coli to T. rex. But still, researchers are starting to find this kind of limiting. Life has evolved ways of using more than 140 amino acids in proteins; and once we start tinkering with the things, we can make scads more. Just because evolution has done so doesn’t mean we need to rely on only these 20 old boring ones. What follows is a look at how and why we want to engineer artificial amino acids into cells and living organisms.