[Campbell Biology P.130] Which of the following statements about collagen and hemoglobin, as... | Practice Question

Which of the following statements about collagen and hemoglobin, as described in the text, is FALSE?

  • A: Collagen is a fibrous protein, whereas hemoglobin is a globular protein.
  • B: Collagen consists of three identical helical polypeptides intertwined into a larger triple helix.
  • C: Hemoglobin consists of four polypeptide subunits, all of which are alpha-helical secondary structure.
  • D: Each hemoglobin subunit contains a nonpolypeptide component called heme, which binds oxygen.

Explanation

The text states that "Both α and β subunits consist primarily of α-helical secondary structure," meaning they are not exclusively or entirely alpha-helical secondary structure. They are complex globular structures that contain other structural elements besides alpha helices.