For the amino acid alanine, the major species in solution at ph 7 is the zwitterionic form, which has a negatively charged carboxylic acid group and a positively charged amino group. there is a less common neutral form in which neither group is charged. the carboxylic acid group of alanine has a pka of 3. the amino group of alanine has a pka of 8. estimate the ratio of the concentration of the neutral amino acid species to the zwitterionic species at ph 7.