Abstract
The two dissociation constants of three amino acid, glycine, alanine, and tryptophan were measured by the conductometric method in the temperature from 15 to 35$^{\circ}$C and pressure up to 2,500bar in aqueous solution. The both dissociation constants were increased as the temperature increased but the pressure effect were not same as the temperature effect. The first constants were increased as the pressure increased but second constants were decreased except tryptophan. The characteristic properties of these amino acids were discussed from the thermodynamic properties of the dissociation reaction. The substituted effects of the reaction were deduced from Hammett reaction and substituted constants which were calculated from the dissociation constants.
세가지 아미노산 즉 글리신, 알라닌 및 트립토판의 두가지 해리상수를 전도도법을 이용하여 온도(15 ~ 35$^{\circ}$C)와 압력(1~2,500bar)을 변화시키면서 측정하였다. 두가지 해리상수는 온도가 높아지면 모두 증가했으나 압력이 높아지면 첫째 해리상수는 증가하고 둘째 해리상수는 트립토판을 제외하면 감소하였다. 이와같은 현상은 반응의 열역학적 성질을 이용하여 설명하였으며 나아가서 반응의 특성을 알아보기 위해서 Hammett의 법칙을 적용하고 반응의 치환기 상수와 압력에 따른 반응상수를 계산하였다. 아미노산의 해리상수의 특성을 치환 효과로 설명하였고 반응의 유형을 반응상수로서 알아보았다.