And all of these types of amino acids are known as alpha amino acids. So let's begin by discussing what an alpha amino acid is. Why do we call an amino acid and alpha amino acid? Well, let's recall some basic organic of chemistry. So we know from organic chemistry that if we have a carbonyl group, so a carbon oxygen double bond, and we have another carbon attached to this carbonyl group, like so then this carbon here is known as an alpha carbon. And for example, if we have a hydrogen atom attached to the alpha carbon, this H atom is known as an alpha hydrogen atom.