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. Now, what is an alpha amino acid? Well, an alpha amino acid contains a center carbon, that is an alpha carbon. And to see what we mean by that, let's take a look at the following diagram, which is basically the general structure of an alpha amino acid.