PH temperature increases. Pure water is neutral, pH 7 at (25 °C), being neither an acid nor a base. Contrary to popular belief, the pH value can be less than 0 or greater than 14 for very strong acids and bases respectively. Measurements of pH are important in agronomy, medicine, chemistry, water treatment, and many other applications. The pH scale is traceable to a set of standard solutions whose pH is established by international agreement. Primary pH standard values are determined using a concentration cell with transference, by measuring the potential difference between a hydrogen electrode and a standard electrode such
6TMS neutral amino acid transporter family the Transporter Classification Database. A gene encoding a small neutral amino acid transporter was cloned from the genome of the hyperthermophilic archaeon "Thermococcus" sp. KS-1. The cloned gene, "snatA", encodes a protein of 216 amino acid residues, SnatA (TC# 2.A.95.1.4), with six membrane-spanning segments (TMSs). Competition studies indicated that SnatA transports various L-type neutral amino acids. It has also been noted that glycine transport is inhibited by a protonophore, FCCP, or valinomycin plus nigericin, indicating that the process is dependent on an electrochemical potential of H. The generalized reaction catalyzed by SnatA is:Amino acid (in) → Amino acid (out) MarC