Further Explanation on Question 7 of Biological and Biochemical Section of GS-Free

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Sep 15, 2015
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Isn't C the more correct answer, because A is only true if you make the assumption that it's at equilibrium (Paragraph 1, Sentence 3)?

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From my reading of the text, C is not as good of an answer because it is not an "assumption" and is not necessarily true in all cases. The text explicitly states that at equilibrium there is far more of the T conformation present and that the substrate being present would shift that relationship toward R. Further, it does not seem universally true that if no substrate is present T and R must be in equilibrium. Other factors, such as temperature, changes in the solution, crowding, etc. could all effect the T:R ratio and make it NOT equal to what it is at equilibrium. The thing that makes A better is that the text goes on to say that substrate drives the equilibrium toward R. Thus if no substrate is present, it is very logical to assume that T predominates (because the factor which drives the ratio away from T is not present).