试题与答案

为探究生物膜的透性,某同学将红甜菜根(液泡中含有花青素)切成大小相同的薄片,分别

题型:多选题

题目:

为探究生物膜的透性,某同学将红甜菜根(液泡中含有花青素)切成大小相同的薄片,分别放在不同温度的蒸馏水中处理1分钟后取出,再分别放在等量清水中浸泡1小时,获得不同温度下的浸出液,然后测定浸出液中花青素吸光度(吸光度大小反映花青素含量多少),实验结果如图。下列相关叙述,正确的是

[ ]

A.花青素通过细胞膜的方式为协助扩散

B.生物膜的选择透过性与蛋白质的种类和数量有关

C.甜菜细胞膜受50℃以上的温度处理后透性大大增加

D.甜菜细胞膜在10~50℃间流动性能力保持不变

答案:

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When did the cafés in France start? The oldest café in Paris is Le Procope. It was opened in 1686 by Francesco Procopio dei Coltelli, the man who turned France into a coffee-drinking society. Le Procope attracted Paris’s political and  43  elite, and in this way played an important part among the upper class. By the end of the 18th century, all of Paris was intoxicated with (沉醉在)coffee and the city   44    some 700 cafés. These were like all-male clubs, with many functioning as centers of  45   life and discussion. By the 1840s the number of cafés had grown to 3,000. The men who gathered in these cafés and  46   the theme of the times included journalists, playwrights and writers. Around the turn of the 20th century, the sidewalk cafés became the meeting halls for artists and literary   47  .

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