Hello, Are the 20 amino acids that are usually referenced when building genetically coded proteins in all of life, and no other amino acids or are these only in humans and animals? I found the sentence below on this website and I wasn't sure what to make of it, is it true that there are hundreds of amino acids in life, depending on the species? This made me wonder about the variety of nucleobases in DNA in different species too. "Only about 20 amino acids are common in humans and animals, with 2 additional ones present in a few animal species. There are over 100 lesser known amino acids found in other living organisms, particularly plants." http://www.scienceclarified.com/Al-As/Amino-Acid.html Any thoughts really appreciated!