问题 单项选择题

胰岛素分子有A、B两条肽链、A链有21个氨基酸,B链有30个氨基酸,胰岛素分子中肽键的数目和脱去的水分子分别是()

A、48、48

B、49、49

C、48、49

D、50、51

答案

参考答案:B

解析:

胰岛素含有两条肽链。A链中有21个氨基酸,则肽键数=脱水数=氨基酸数-肽链数=21-1=20个。B链有30个氨基酸,则肽键数=脱水数=氨基酸数-肽链数=30-1=29.胰岛素分子中肽键数=A链中肽键数+B链中肽键数=20+29=49个。脱水数=A链中脱水数+B链中脱水数=20+29=49个。故B正确。

考点:本题考查了氨基酸合成蛋白质的相关内容,意在考查考生理解所学知识的要点,把握知识间的内在联系的能力。

填空题
阅读理解

The Statue of Liberty(自由女神像)is one of the most famous tourst places in the United Stafes.However,it wasn’t the Americans who designed and built it It was given as a gift of friendship from France.

In 1865,a young French artist named Bartholdi took part in a big party near the town of Versailles.At the party,someone hoped to give America a special gift for the country’s hundredth birthday in 1876.Bartholdi was interested in the idea and suggested a big statue of some kind.Back home,he thought about it for the next six years.By 1871,Bartholdi had planned most of the details of the statue.It was going to be a lady calld Liberty,who held a torch(火把)high over her head in hear right hand and a book close to her body in her left hand.It seemed that she was lighting the way to freedom.

But it was such a huge project that a large amount of noney was needed.And also,for many resaon,Bartboldi and his team couldn’t finish it on time.The big statue wasn’t finished until June 1884.On July22,1885,it arrived in New York from France by water.The statue was finally placed on a small island called Manhattan near New York in April 1886.

根据材料内容选择最佳答案。

小题1:Who first had the idea of giving a hundredth birthday gift to America?

A,The host of the party.   B.The president of France

C.Bartholdi     D.It isn’t mentioned

小题2:We know the United States of America was set up in _____ according to the passage.[

A.1765

B.1771

C.1776

D.1786小题3:What’s in the left hand of the lady called Liberty?

A.A book

B.A fan

C.A torch

D.A hat小题4:The statue was carried to New York _____ after it was finished.

A.on the airplan

B.on the sea

C.in the car

D.on the train小题5:Which of the following is TRUE,according to the passage?

A.The statue of Liberty was built by an American who lived in France.

B.The building of the statue of Liberty cost much mony.

C.The building of the statue of Liberty was finished in 1886.

D.The ststue of Liberty appeared in New York on time.