Use the following information when answering the corresponding question(s).
Shu-ichi Nakano reported in Science in February 2000 that "The RNA enzyme (ribozyme)from hepatitis delta virus catalyzes self-cleavage of a ...[chemical] ...bond." This reaction is inherently slow due to the formation of an unfavorable negative charge on the ribozyme.The author goes on to show that this self-cleavage is made faster by joining it with an acid-base reaction that neutralizes the negative charge.Nakano's model describes a positively charged cytosine base on the ribozyme acting as the acid,and magnesium hydroxide acting as the base.Specifically,the cytosine donates its proton (H⁺)to neutralize the unstable negative charge that would have formed on the ribozyme.
-Refer to Nakano's quote.What can be inferred about the free-energy profile for the self-cleavage reaction from the information provided in the paragraph?
A)It must be endergonic.
B)It must be exergonic.
C)It must be endothermic.
D)It must be exothermic.

Question

Quizplus · Accepted Answer

The fact that the RNA enzyme catalyzes self-cleavage suggests that it is energetically favorable, which would correspond to an exergonic reaction. The information provided does not suggest anything about whether the reaction is endothermic or exothermic.

Use the Following Information When Answering the Corresponding Question(s)