PH is dissolved in water, the pH will be greater than 7. A solution of a strong acid, such as hydrochloric acid, at concentration 1 mol dm has a pH of 0. A solution of a strong alkali, such as sodium hydroxide, at concentration 1 mol dm, has a pH of 14. Thus, measured pH values will lie mostly in the range 0 to 14, though negative pH values and values above 14 are entirely possible. Since pH is a logarithmic scale, a difference of one pH unit is equivalent to a tenfold difference in hydrogen ion concentration. <br> The pH
6TMS neutral amino acid transporter family 6TMS neutral amino acid transporter family The 6TMS Neutral Amino Acid Transporter (NAAT) Family (TC# 2.A.95) is a family of transporters belonging to the Lysine Exporter (LysE) Superfamily. Homologues are found in numerous Gram-negative and Gram-positive bacteria including many human pathogens. Several archaea also encode MarC (see below) homologues. Some of these organisms have 2 or more paralogues. Most of these proteins are of about the same size (180-230 aas) although a few are larger. They exhibit 6 (or in some cases, possibly 5) putative TMSs. A representative list of members belonging to the NAAT family can be found in