题干

为了研究温度对某种酶活性的影响,设置 三个实验组:甲组(15℃)、乙组(35℃)和丙组(55℃),在其它条件相同的情况下,测定各组在不同反应时间内的产物浓度,结果如图所示。下列说法错误的是(      )

A:三个温度条件下,该酶活性最高的是乙组

B:在时间t1之前,如果甲组温度提高10℃,则酶促反应的速度会加快

C:在t2时,如果向丙组反应体系中增加2倍量的底物,其他条件保持不变,则在t3时,丙组产物总量将增加2倍

D:在t2时,如果向乙组反应体系中增加2倍量的酶,其他条件保持不变,则在t3时乙组产物总量不变

上一题 下一题 0.0难度 选择题 更新时间:2017-12-12 07:41:43

答案(点此获取答案解析)

C

同类题5

完形填空
    A few years ago, I took a sightseeing trip to Washington D.C. I saw many of our  1  treasures, and I also saw a lot of   2  people like beggars and homeless folks in the streets.
    Standing outside the Ronald Reagan Center, I heard a voice say, “Can you help me?” When I turned around, I saw an elderly   3 woman with her hand extended(伸出). In a natural reaction, I reached into my pocket, pulled out all of my loose change and   4  it on her hand. I didn't even look at her. I was  5  at being troubled by a beggar.
     6 the blind woman smiled and said, “I don't want your money. I just need help finding the post office.”
    Immediately, I realized what I had done. I  7  with prejudice(偏见)—I judged another person simply for what I   8  she was.
    The thing I had forgotten about myself is 9  I am an immigrant(移民). I left Honduras and arrived in America at the age of 15   10   the years, I have been a dishwasher, cashier, mechanic and pizza delivery driver among many other 11, and finally I became a network engineer.
    In my own life, I have experienced many open acts of prejudice. I remember a time, at age 17—I was a busboy, and I heard a father told his little boy that if he did not do well at school, he would   12  like me.
    But now, living in my American middle-class lifestyle, it is too easy to forget my past, to forget who I am and where I have been, and to lose sight of 13  I want to be going. That blind woman on the street of Washington D.C. cured me of my  14  . She reminded me to always keep my eyes and heart   15 .