BY THE USE OF TWO EXTREME MODELS: a hydrated sphere and an unhydrated rod the valence (net charge) of corpuscular proteins can be successfully calculated from electric mobility data by the Debye-Hückel theory (modified to include the effect of the ions in the ion atmosphere) in conjunction with the electrophoretic theory of Henry. As pointed out by Abramson, this permits a comparison with value...

A new chromogenic, self-assembled molecular capsule G@22 is developed by introducing four (N,N-dimethyl-4-aminophenyl) azobenzyl moieties on the upper rim of a resorcin[4]arene-based amidoimino-cavitand. The tuning of conjugation between amido and (N,N-dimethyl-4-aminophenyl)azobenzyl groups by acid-base titration allows naked-eye detection of molecular capsule formation.

The research objective was to describe the communication and collaboration skills of high school students in learning acid-base titration with guided inquiry problem-based models. This type is library descriptive analysis. Secondary data used are literature form books, journals assessment rubrics. collection method a documentation Miles Huberman Based on results review, it found that models occ...

Artificial bacteriorhodopsin pigments based on synthetic retinal analogues carrying an electron-withdrawing CF3 substituent group were prepared. The effects of CF3 on the spectra, photocycles, and Schiff base pKa values of the pigments were analyzed. A reduction of 5 units in the pKa of the Schiff base is observed when the CF3 substituent is located at the C-13 polyene position, in the vicinity...

A new, simple and accurate method is introduced for determining H(2)CO(3)(*) alkalinity in fresh waters dominated by the carbonate weak-acid system. The method relies on a single H(3)PO(4) dosage and two pH readings (acidic pH value target: pH~4.0). The computation algorithm is based on the concept that the overall alkalinity mass of a solution does not change upon the addition of a non-proton-...

G-quadruplexes are higher-order nucleic acids structures formed by G-rich sequences that are stabilized by tetrads of hydrogen-bonded guanine bases. Recently, there has been growing interest in the study of G-quadruplexes because of their possible involvement in many biological processes. Isothermal titration calorimetry (ITC) has been proven to be a useful tool to study the energetic aspects o...