<prompt> What changes the conformation of alpha helix in collagenMethionineProlineAlanineTyrosine  <response>: Ans. b ProlineRef: Harpers Biochemistry, 30th ed. pg. 141, 298-99 Proline is the amino acid which changes the conformation of the alpha helix in collagen due to the nature of proline having a cyclical structure. It also forms the ends of the beta sheets in the secondary structures. 