Wow, that’s a big 3d printer! (If you’ve ever printed spaghetti on a smaller 3d printer then you know)

Proteins are made from amino acids, same as words are made from letters. If you eat a protein source that’s short on some of those letters then you need to mix it with a source that has more of them… Otherwise you can’t create all the proteins that you need. (It’s a bit more complicated, but that’s the bit that you need here)