Photo AI
Which structure shows the zwitterion of an amino acid? A H₃N⁺ — CH — COO⁻ | H₂C — CH₂ — CH₂ — NH₃⁺ B H₃N⁺ — CH — COO⁻ | H₂C — COO⁻ C H₂N — CH — COO⁻ | H₂C — OH₂ D H₃N⁺ — CH — COO⁻ | H₂C — SH - AQA - A-Level Chemistry - Question 30 - 2020 - Paper 3
Question 30
Which structure shows the zwitterion of an amino acid? A H₃N⁺ — CH — COO⁻ | H₂C — CH₂ — CH₂ — NH₃⁺ B H₃N⁺ — CH — COO⁻ | H₂C — COO⁻ C H₂N — CH —... show full transcript
Worked Solution & Example Answer:Which structure shows the zwitterion of an amino acid? A H₃N⁺ — CH — COO⁻ | H₂C — CH₂ — CH₂ — NH₃⁺ B H₃N⁺ — CH — COO⁻ | H₂C — COO⁻ C H₂N — CH — COO⁻ | H₂C — OH₂ D H₃N⁺ — CH — COO⁻ | H₂C — SH - AQA - A-Level Chemistry - Question 30 - 2020 - Paper 3
Step 1
Which structure shows the zwitterion of an amino acid?
Answer
The zwitterion of an amino acid is characterized by the presence of both a positively charged amino group ( ext{-NH₃}^+) and a negatively charged carboxylate group ( ext{-COO}^-). Looking at the provided structures:
- Option A has a positively charged amino group and a negatively charged carboxyl group, making it a zwitterion.
- Option B also has a positively charged amino group, but it contains another negatively charged carboxyl group, indicating it's not a zwitterion.
- Option C lacks the positive charge on the amino group, thus not representing a zwitterion.
- Option D is the same as option A and correctly shows the zwitterion structure.
Thus, the correct answer is D.