题干

如图甲、乙为组成生物体的相关化合物,乙为一个由α、β、γ三条多肽链形成的蛋白质分子,共含271个氨基酸,图中每条虚线表示由两个巯基(﹣SH)脱氢形成一个二硫键(﹣S﹣S﹣).下列相关叙述错误的是(  )

A:甲为组成乙的基本单位,且乙中含有20种不同的甲

B:由不同的甲形成乙后,相对分子量比原来少了4832

C:甲形成乙的场所在细胞质、线粒体、叶绿体中均存在

D:如果甲中的R为C3H5O2,则由两分子甲形成的化合物中含有16个H原子

上一题 下一题 0.0难度 选择题 更新时间:2015-02-05 11:05:30

答案(点此获取答案解析)

A

同类题1

阅读下面短文,从短文后各题所给的四个选项(A、B、C和D)中,选出可以填入空白处的最佳选项。

    It was a cloudy day, and the terrible experience happened when I was studying in Bangalore. I got a call from my mom that my brother's1was fixed and they were arranging the wedding ceremony in the next few days.My 2was pretty far. So the next thing I was 3 to do was to book my 4 ticket as there was no direct flight to my hometown. The 5 was done by an agent in my neighborhood. I paid the whole amount 6. But when the day approached the 7 disappeared, leaving me without the train ticket, and thus 8all my travel plan.

    But as it is said, once you face such 9 situations, you realize your inner strength. I 10 decided I would complete my whole journey by bus. Without further 11, I took a bus to the first city stop. The next bus was again not 12 —it was 8 hours to a city near my hometown, where my aunt lived. They were also going to 13 my brother's wedding ceremony. So I called them and 14 them to accommodate me. They 15. Half the battle was won.

    Then next day, I was just a few hours from my hometown. When my aunt's family and I were boarding our car, my 16 asked me to switch places with her.

    The journey continued. We were trying to overtake(超越) another car when 17 a truck appeared in front of us and we went directly head on in front of it. We 18 with the truck. In this accident, almost everyone in our car was 19. Fortunately, I didn't have any injury, 20my cousin who switched places with me was seriously injured!