题干

根据下面的化学结构式回答问题.

(1)该式中,A表示____ ,B表示____ ,C表示____ .

(2)该式表示____ 化合物,含有____  个肽键.

(3)该化合物由____ 个氨基酸分子失去____ 分子水形成,这种反应叫____ 

(4)该式中的氨基酸种类不同,是由____ 决定的.

(5)若氨基酸的平均相对分子量为90,则蛋白质的相对分子质量约为____ .

上一题 下一题 0.0难度 选择题 更新时间:2019-04-12 05:05:19

答案(点此获取答案解析)

氨基,肽键,羧基,三肽,2,3,2,脱水缩合,R基,234

同类题4

阅读理解

阅读下列短文,从每题所给的四个选项(A、B、C和D)中,选出最佳选项。

    You may not know a lot of people when you start high school. Even if you know some new students, you still feel nervous that you don't know any upperclassmen (高年级学生) and teachers. How are you going to make friends among this sea of unknown faces?

    Most high schools welcome new students before school actually starts. These are helpful not only because you learn your way around the buildings and get to meet some of your teachers, but also because you get to meet new students. That way, when you show up on your first day of school, you may already recognize a few familiar faces.

    When you talk to people, you'll probably find that a lot of them are feeling just like you. They're all new to the school and don't know what to expect. Talking about a common concern with your classmates can help you develop friendships.

    The work in high school is something freshmen are probably worried about. The work in high school builds on what you learned in middle school, giving you a more advanced knowledge of many subjects. So you may find you have more work to do or that it's a bit more challenging (有挑战性的). If you ever find your work too difficult, teachers can give you extra help.

    High school also has more activities after class than middle school, such as clubs, music and theater groups and sports teams. This is a good time to explore your interests and try new things.

    Middle school taught you the basics of academics, time management, and social skills while providing you with a little extra support and guidance. High school gives you the chance to learn how to be more independent (独立的) and responsible (有责任的).