问题 单项选择题

青霉素类药物的抗菌机制是

A.抑制细菌二氢叶酸还原酶
B.抑制细菌二氢叶酸合成酶
C.抑制细菌蛋白质合成
D.抑制细菌DNA螺旋酶
E.抑制细菌细胞壁的合成

答案

参考答案:E

解析:[试题难度] 14.易;15.易
[认知层次] 14.解释;15.记忆

题14:本题是理解题,考查学生对磺胺类药物抗菌机制的了解。许多细菌不能利用现成叶酸.必须依赖自身二氢叶酸合成酶催化蝶啶和对氨基苯甲酸合成二氢蝶啶,再与谷氨酸生成二氢叶酸,并在二氢叶酸还原酶作用下变成四氢叶酸,而磺胺类药物与对氨基苯甲酸结构相似,可与对氨基苯甲酸竞争二氢叶酸合成酶,从而阻止了细菌二氢叶酸合成,继之四氢叶酸合成减少,导致细菌生长繁殖的抑制。
题15:本题是记忆判断题,考查学生对青霉素类药物抗菌机制的了解。青霉素类药物可与青霉素结合蛋白结合,抑制转肽作用,阻碍了肽聚糖的交叉联结,导致细菌细胞壁缺损,丧失屏障作用,使细菌细胞肿胀、变形、破裂而死亡。

阅读理解

阅读理解。

     Being a youth is one thing, and being a good one is another. A good youth should have these qualities

(品德): First of all, health. A healthy body is the best riches. Without it, nothing can be done well. If you

are poor in health, you will have to take medicine day after day. You can even work, do sports and so on.

Secondly, one must be of good quality. Always do something good for others. Help those in trouble and

care about the people around you. If everyone did the same, what a wonderful world this would be! Thirdly,

one must have the ability (能力) to work with others. Cooperation and communication (合作和交流) are two

important keys to better human relations. Everyone needs friends because no one can live through life alone

or do everything he wants to.

     Besides the examples above, patriotism is the one we should never forget. Patriotism means a love for

one's country. It is one of the highest qualities of human's. Everyone should love his own country. But people

sometimes think that patriots (爱国者) must be fighters or that they live in a time of fighting for their country.

That is wrong. A good youth's work is not only fighting. A good youth will do the things his country asks him

to do. I think a good youth of today should also have some training in art. If everyone can enjoy art and be able

to make more of it for others, then people will live better and enjoy more.

1. What's the first thing a good youth should have?

A. A healthy body.

B. The best riches.

C. The good ability.

D. The patriotism.

2. A person who has good qualities should ________.

A. think of himself

B. help others that need help

C. help the people they know

D. always do as others do

3. The writer tells us that working with others is ________.

A. good for some people

B. important for everyone

C. not necessary to good friends

D interesting

4. From the passage we know the patriots must be ________.

A. fighters to protect their countries

B. people who fight for their countries

C. people who do what their country wants them to do

D. fighters live in a time of fighting for their country

5. It you want to be a good youth of today, ________.

A. you should live alone

B. you should also know art

C. you can keep your own ideas

D. you should fight for your country

判断题