When an amino acid is placed at its isoelectric point (pI) it's a zwitterion. What of if it's placed in a pH lesser or greater than it's pI, what happens? If I am correct a lesser pH (than pI) means an ACIDIC environment, meaning a high level of H+ ions. Hence the NH2 gets protonated forming NH3+ and the COOH, deprotonated, forming COO-. Therefore, the amino acid is now BASIC. So my question is, is it that an amino acid carries a charge opposite to the 'charge' (or so to say) of it's environment, in the sense that if the amino acid is basic then that means it's in a pH lesser than it's pI (e. g. a pH of 3), while if the amino acid is acidic that means the pH lies between 8-14, hence basic, or generally above it's pI. If this is the case, why is it so please?? I will really appreciate help with this. Thanks!!!​