So these two molecules are structurally similar, so they have very similar structures. The only difference is at a PH of about seven, which is the physiological PH, this exists without a charge, while this tryptophan amino acid exists in its zvitarion form. So we'll have a full negative charge and a full positive charge. And because this actually contains full charges and this one doesn't, the end, though, is 1000 times more likely to actually pass across that cell membrane and dissolve in that hydrophobic core section than that tryptophan amino acid. So we see that indo, an uncharged molecule that is structurally similar to the tryptophan amino acid, crosses the membrane 1000 times more likely or more quickly than the tryptophan in its zvitarion form, which is the form that exists at the physiological PH of around seven. Now, so we can basically summarize the following result.