Biology 9700 · AS & A Level · Proteins

Proteins — practice question

Which row shows the correct description of both a collagen molecule and a collagen fibre?

  • Acollagen molecule: $\alpha$ and $\beta$ polypeptide chains forming a double helix, held together by disulfide bonds; collagen fibre: molecules of collagen arranged randomly to each other, linked by hydrogen bonds
  • Bcollagen molecule: a polypeptide chain, with repeating amino acids, forming an $\alpha$-helix; collagen fibre: three molecules of collagen, forming a triple helix, held together by hydrogen bonds
  • Ccollagen molecule: a polypeptide chain, with three repeating amino acids, forming a helix; collagen fibre: three $\alpha$ helical collagen molecules, forming a triple helix, held together by ionic bonds
  • Dcollagen molecule: three helical polypeptide chains, forming a triple helix, held together by hydrogen bonds; collagen fibre: molecules of collagen lying parallel and cross-linked to each other

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