So what are these seven amino acids? So we have aspartic acid and glutamic acid, Aratu, acidic amino acids, and the rest are histidine, cysteine, lysine, tyrosine, and arginine. Now, on top of these ionizable side chain groups found on these seven amino acids, every one of our amino acids also contains ionizable alphacroboxyl groups and ionizable alpha amino group. So remember, every single alpha amino acid contains a central carbon that is bound onto a carboxyl group and onto an amino group. Now, let's take a look at the following table and discuss what it actually tells us. So, the first column basically describes that particular ionizable group or that particular ionizable amino acid.