And so now we have one, two and three. And we basically have to follow this order, one to three. And we draw our arrow and notice the arrow points in the counterclockwise direction. And that means it's the S. If it pointed in the clockwise direction, that would mean it would be an R ABS configuration. So the majority of the L isomers in our body have the S ABS configuration, as shown in the following diagram. Now, earlier I said that this is a protein version of the amino group.