And let's compare it to this diagram we've drawn right here. So let's suppose that the other group attached to this carbon is an oxygen group. So what that means is this entire group here is a carboxylic acid group in which this oxygen has been deprofename. So we have a negative charge here. So what an alpha amino acid is, if it's basically a molecule that contains a sensor carbon, that is an alpha carbon. And so it contains this carboxylic acid group that has been deprotonated as shown in the following diagram.