The solubility of the a.a. in water perhaps is the criteria.
Since the sidechains differ, the net charge on the side chains (individual
groups) give a numeric value which when normalized against Glycine could
(to me) mean the hydrophobicity of that a.a.
The pH should be 7 for the measurments to be made.
So my answer is-
1) Y, W & F
2) R
salim
S Mottagui-Tabar
Department of Microbiology
Stockholm University
106 91 Stockholm
SWEDEN
E-Mail Salim@mibi.su.se
Fax - 46 8 612 9552
Tel - 46 8 16 41 57