本题目来源于试卷: Interaction & Interdependence C.1 Enzymes & Metabolism，类别为 IB生物学
[单选题]
Which of the following statements are true rega2-n;dtt j(gzx3,a (nvj jth9g rding regulation by end-2o) xh*tail+ ,l*aon x1uraw5product i a+xl1 t 2,oa)oh5xn l*wiur*anhibition?
I. The end product binds to the allosteric site of the enzyme.
II. The binding of the end product is reversible.
III.End product inhibition is an example of negative feedback regulation.
A. I only
B. I, II only
C. I, III only
D. I, II and III
参考答案: D
本题详细解析:
In many metabolic re(a klerc/ +2av/p1/ p wqek0boactions, the product of the last reaction acts as an inhibitor and binds to the allosteric site of the enzyme that catalyses the first reaction in the pathway (Statement I). The binding is reve(2 baqp0v l okp/ca+/we/e1krrsible, and when the end product is removed, the enzyme goes back to its original conformation where the active site can bind to the substrate (Statement II). It is an example of negative feedback. When there is an excess of the product, the pathway is switched off. When there is less of the end product, the pathway is switched on by the detachment of the end product from the enzyme that catalyses the first reaction (Statement III).
Only Choice D has all the correct statements mentioned (I, II and III).
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