Table 3 illustrates the ratio of solubility of an amino acid in gm. /ml. as compared to the solubility of glycine in water. It can be seen that the addition of a methyl group to the basic glycine molecule reduces solubility by 34 percent, while the addition of the isopropyl group re-duce s solubility by 7 3 percent.able 3 illustrates the ratio of solubility of an amino acid in gm. /ml. as compared to the solubility of glycine in water. It can be seen that the addition of a methyl group to the basic glycine molecule reduces solubility by 34 percent, while the addition of the isopropyl group re-duce s solubility by 7 3 percent.