Amino acids are a sort of self-contradiction because they contain both a basic group (the NH₂ end) and an acidic group (the CO₂H end) in the same molecule. Therefore, it should not surprise you that, when dissolved in water, an amino acid can react with itself to form what is known as a zwitterion. Based on this information, 

(a) Draw the structural formula for the form of the amino acid alanine you would expect to find in a neutral water solution. What is the net electrical charge on this species?

(b) Enough concentrated HCl is added to the solution of part (a) to make it strongly acidic. Draw the structural formula for the form of alanine you expect to find in this solution. What is the net charge on the alanine?

(c) Enough concentrated NaOH is added to the solution of part (a) to make it strongly basic. Draw the structural formula for the form of alanine you expect to find in this solution. What is the net charge on the alanine now?