試題詳解

31. Which one of the following statements relating to proteins is correct?
(A) All proteins have quaternary structure.
(B) Histidine is often found at the active site of globular proteins.
(C) The primary structure of a protein describes the amino acid composition, but not the amino acid sequence.
(D) Both alpha-helix and beta-sheet segments occur as secondary structural elements in all proteins.
(E) When proteins are denatured, they can never be reconstituted back to a functional state.