Ambiguity on this BIO question

[Demps]

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Disulfide bridges are part of which protein structural level?

A. Primary.
B. Secondary.
C. [Correct] Tertiary.
D. Quaternary.
E. [Yours] More than one of the above.

"Choice D is incorrect because quaternary protein structure corresponds to the arrangement of multiple polypeptide chains, which does not apply to this question because it specifically states that the protein is composed of a single polypeptide chain."


shouldn't it also include quaternary structure because it is made up of multiple tertiary structures which contain disulfide bonds. Is it just poor wording of the question? What do you guys think?

 

[LetsGo2DSchool]

This was discussed in detail about a week ago so you may want to do a search and try to find the thread. I believe both C and D are correct answers, however, for purposes of DAT, go with C.

 

[CoolRX]

Disulfide bridges are part of which protein structural level?

A. Primary.
B. Secondary.
C. [Correct] Tertiary.
D. Quaternary.
E. [Yours] More than one of the above.

"Choice D is incorrect because quaternary protein structure corresponds to the arrangement of multiple polypeptide chains, which does not apply to this question because it specifically states that the protein is composed of a single polypeptide chain."


shouldn't it also include quaternary structure because it is made up of multiple tertiary structures which contain disulfide bonds. Is it just poor wording of the question? What do you guys think?

This may just be poor wording of the question, and one I might have gotten wrong myself. I recently reviewed this however and it is still fresh knowledge. For the sake of this argument, to add to this confusion, imagine the question asked:

Sequence of amino acids is part of which protein structural level?

Obviously, primary structure relate to that, but without primary structure there would be no secondary, tertiary or quaternary. However, sequence of amino acids mainly refers to primary structure. And the same goes for the question you asked. While quaternary structure does compose of multiple subunits of polypeptides from tertiary structure, disulfide bridges makes tertiary structures what they are.

I agree the question is confusing, and in my haste, I might have gotten it wrong myself. Hope this clears any confusion.