问题 填空题

(1)蛋白质水解得到________,进一步水解,最后得到____________。一个蛋白质分子可以含有一条或多条肽链,肽链中有很多肽键,一个肽键中的氧原子与另一个肽键中氨基的氢原子通过________连接,形成类似于_____________的结构,最后形成具有三维空间结构的蛋白质分子。

(2)一定条件下,可使两分子氨基酸失去一分子水缩合为:“二肽”,今使甘氨酸和丙氨酸

 混合反应,生成的“二肽”最多为__________种。

答案

(1)多肽;氨基酸;氢键;螺旋状

(2)4

阅读理解

Can plants eat people? Probably not,but there are many plants that eat meat.Some of them are big.And they can eat small animals.One famous meat-eating plant is the Venus flytrap(捕蝇草).

The Venus flytrap is a very strange plant.It grows in dry parts of the United States.Its leaves are like the pages of a book.They can open and close very quickly.Inside the leaves,there are three small hairs.If a fly touches one of the hairs,the leaf closes quickly.The fly cannot get out.In about half an hour,the leaf presses the fly until it is dead.Then,the plant covers the fly.Slowly,the plant eats the fly.

Why do plants do it? Most plants get what they need from the sun,the air,and the ground.In some places,the ground is very poor.It doesn’t have all these important things,

especially nitrogen(氮).Animal meat has a lot of nitrogen, so some plants eat meat to get what they need.Let’s hope that some of the bigger plants don’t get the same idea !

小题1:The Venus flytrap is a kind of_________.

A.plant

B.animal

C.food

D.meat小题2:The Venus flytrap grows in_________.

A.most parts of the world

B.some parts of Africa

C.dry parts of the United States

D.wet parts of England小题3:From the passage,we learn that_________.

A.all plants can eat people

B.all plants can eat animals

C.some plants can eat people

D.some plants can eat animals小题4:The underlined word“presses”probably means________ in Chinese.

A.挤压

B.关上

C.打开

D.松开小题5:—Why do some plants eat animal meat? —Because_________.

A.plants are dangerous to animals

B.animals are dangerous to plants

C.plants want to get what they need from animal me

D.plants want to protect themselves against animals

判断题