BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Amino acids in solution at neutral pH exist predominantly as zwitterions. In dipolar from the amino group is protonated (−NH2+) and the carboxyl group is deprotonated (−COO−). The ionization state of an amino acid varies with pH.

Detailed explanation-2: -An amino acid has this ability because at a certain pH value (different for each amino acid) nearly all the amino acid molecules exist as zwitterions. If acid is added to a solution containing the zwitterion, the carboxylate group captures a hydrogen (H+) ion, and the amino acid becomes positively charged.

Detailed explanation-3: -Almost all amino acids exist as zwitterions at a certain pH value, which is different for each amino acid. Glutamine only behaves simultaneously as an acid and as a base at pH 7, which means it is only zwitterionic at pH 7.

Detailed explanation-4: -The most acidic carboxyl will be deprotonated and negatively charged, the less acidic carboxyl remains protonated and thus neutral. The pH is still too acidic for the amino group, which remains protonated and positive. This gives us a net charge of 0 and our zwitterion form.

Detailed explanation-5: -Zwitterions are simultaneously electrically charged and electrically neutral. They contain positive and negative charges, but the net charge on the molecule is zero.