Which of the following amino acids is unlikely to be found in an a-helix due to its cyclic structure?
A) phenylalanine
B) tryptophan
C) proline
D) lysine

Question

Quizplus · Accepted Answer

Proline is unlikely to be found in an alpha helix because of its cyclic structure which limits its flexibility to participate in the regular primary structure of the helix. The other amino acids listed (phenylalanine, tryptophan, and lysine) can all be found in an alpha helix.

Which of the Following Amino Acids Is Unlikely to Be