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        本题目来源于试卷:  Interaction & Interdependence C.1 Enzymes & Metabolism ,类别为 IB生物学 
[单选题]In an experiment, the k2uj2wiy 6u  *k04 jzw-hjbhzy3k;n3 feffwxum x;y axo6,(od); aect of increasing temperature on the efficiency of lactase acya( o,x;; x 6ouxw)admtivity is tested. Which is an appropriate dependent variable for this experiment?
 
 
 
A. Change in temperature B. Variation in pH
 C.  Change in lactase concentration
 D.  Rate of glucose production
 
 
 参考答案:  D
 
 
 本题详细解析:
 The lactase enzyme hydrolyzes  v*-i6 mlzogk:, wan4athe disaccharide lactose into the monosaccharides glucose and galactose. So, an appropriate dependent variable for the experiment is the rate at which one of these products is formed. Therefore, the rate of formation of glucose is an appropriate dependent variable for this experiment.
The change in temperature (Choice A) is the independent variable (the variable being tested) and so is not an appropriate dependent variable. pH (Choice B) does not change when lactose is broken down into glucose and galactose, so it would not indicate the activity of the enzyme. An enzlo g,:w6n  ikm-v*4zaayme is not consumed in a reaction, so there will be no change in lactase concentration (Choice C).
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