So let's move on to the side chain group of that amino acid number one. We see that we have our histidine. And so this at a PH of six or above, will begin to lose that H atom. And since where at a PH of seven, what that means is this will have lost the H atom, it will have a neutral charge. And so now we have a charge of zero for the second case, for that first side chain group. Now the second side chain group and the second amino acid is tyrosine.