本题目来源于试卷: Interaction & Interdependence C.2 Cell Respiration，类别为 IB生物学
[单选题]
The graph shows the 3v83rba*j; * xa v6wy fr z-zyot7ji5pamount aa0 m5m 9zhxm.of oxygen inside a chamber containing yeast cells and substrates as measured by an oxygen sensor. The experimental investigation compared the rate of oxygen consumption during aerobic respiration by the yeast cells using three different substrates: sucrose, fru a5a mm .zx90hmctose and glucose.
What can be concluded from the graph?
A. The hydrolysis of sucrose forms glucose and fructose
B. The breakdown of glucose and fructose is much slower than sucrose
C. The rate of cellular respiration decreases the more complex the substrate
D. The cumulative amount of oxygen consumed by the yeast cells increases over time
参考答案: D
本题详细解析:
Inside a chamber containing yeast cells and one substrate, the yeast cells un7sg o5 svkmwm8)ugj 98dergo aerobic cellular respiration in the presence of oxygen to break down the sugar substrate to form carbon dioxide and water. The amount of oxygen present inside the chamber can be measured using aw jg u8m7gkss598vom)n oxygen sensor in the units of parts per million (ppm). As the yeast uses oxygen, the amount of oxygen present inside the chamber decreases. This can be seen from the graph.
All three substrates are broken down by yeast. Even though hydrolysis of sucrose does form glucose and fructose (Choice A), this cannot be deduced from the graph presented. In the graph presented, all three substrates are broken down at similar rates. Lines of best fit are close together, so we cannot conclude which substrate is getting metabolised slower than the others. (Choice B)
The graph shows the amount of oxygen inside the chamber decreasing over time. The rate of cellular respiration between the three substrates is similar. The respiration rate seems to be faster (not slower) with sucrose. (Choice C)
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