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, th5y5itva)*l2jcmou ev./ r y8 ue effect of increasing temperature on the ef q31 ;xjvw)4pelr8tfqficiency of lactase wflq )r ;e xpqtj384v1activity 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 the disaccharide lactxk6jou*gok6 v7vi6 + wose 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 testuojkvx*+6gkvo w 6 i67ed) 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 enzyme is not consumed in a reaction, so there will be no change in lactase concentration (Choice C).
|