学位英语

Using enzymes commonly found in living cells，a new type of fuel cell produces small amounts of electricity from sugar.If the technology is able to succeed in mass production，you may some day share your sweet drinks with your cell phone.

In fuel cells，chemical reactions generate electrical currents.The process usually relies on precious metals，such as platinum.In living cells，enzymes perform a similar job，breaking down sugars to obtain electrons and produce energy.

When researchers previously used enzymes in fuel cells，they had trouble keeping them active，says Shelley D.Minteer of St Louis University1.Whereas biological cells continually produce fresh enzymes，there’s no mechanism in fuel cells to replace enzymes as they quickly degrade.

Minteer and Tamara Klotzbach，also of St Louis University，have now developed polymers that wrap around an enzyme and preserve it in a microscopic pocket.“We tailor these pockets to provide the ideal microenvironment” for the enzyme，Minteer says.The polymers keep the enzyme active for months instead of days.

In the new fuel Cell，tiny polymer bags of enzyme are embedded in a membrane that coats one of the electrodes.When glucose from a sugary liquid gets into a pocket，the enzyme oxidizes it，releasing electrons and protons.The electrons cross the membrane and enter a wire through which they travel to the other electrode，where they react with.oxygen in the atmosphere to produce water.The flow of electrons through the wire constitutes an electrical current that can generate power.

So far，the new fuel cells don’t produce much power，but the fact that they work at all is exciting，says Paul Kenis，a chemical engineer at the University of Illinois2 at Urhana-Champaign3.“Just getting it to work.” Kenis says，“is a major accomplishment.”

Sugar-eating fuel cells could be an efficient way to make electricity.Sugar is easy to find. And the new fuel cells that run on it are biodegradable，so the technology wouldn’t hurt the environment.The scientists are now trying to use different enzymes that will get more power from sugar.They predict that popular products may be using the new technology in as little as 3 years.

词汇：

enzyme/5enzaIm/n.酶 electrode/I5lektrEJd/n.电极platinum/5plAtinEm/n.铂，白金 membrane/5membrein/n.膜，薄膜

electron/I5lektrRn/n.电子 oxidize/5Cksi7daiz/v.氧化degrade/di5reid/v.降解 glucose/5lu:kEus/n.葡萄糖

polymer/5pClimE/n.聚合物 biodegradable/7baiEudi5reidEbl/adj.能进行生物降解的

microenvironment n.微环境 embed/im5bed/v.埋置，插入

proton/5prEutCn/n.质子

试题

1. According to the first paragraph，when can we share our sweet drinks with our cell phones?

A When enzymes can be commonly found in living ceils.

B When the technology of producing a new type of fuel cell appears.

C When the technology of a new type of fuel cell is suitable for mass production.

D When the technology of mass producing cell phones appears.

2. What trouble did Minteer and Klotzhach have in their research?

A They had trouble keeping enzymes in fuel cells active.

B They had trouble keeping biological cells active.

C They had trouble producing fresh enzymes.

D They had trouble finding mechanism for producing enzymes.

3. According to Paragraph 5，electrons are released

A when bags of enzyme are embedded in the new fuel cell.

B when glucose from a sugary liquid goes through the enzyme.

C when the enzyme oxidizes the glucose from a sugary liquid that goes through

a pocket.

D when the enzyme oxidizes the sugary liquid that goes through a pocket.

4. What is exciting about the new fuel cells?

A Their limitless power generation capacity is amazing.

B Their limited power generation capacity is a good beginning.

C Their limited power generation capacity is the result of great efforts.

D Their limitless power generation capacity is a major accomplishment,

5. According to the last paragraph，what is NOT true of the new fuel cells?

A The new fuel cells run on sugar that is easy to find.

B The new fuel cells are environment friendly.

C The new fuel cells are biologically degradable,

D It will take some time before the new fuel cells can be used in popular products.

答案与题解：

1. C A和D明显不是正确答案。B不是正确选择，因为只有当这种新的燃料电池被大规模生产时，才有可能实现用甜饮料给手机提供电能。

2. A 文章第三段的第一句是问题的答案。

3. C 该段第二句“When glucose from a sugary liquid penetrates a pocket，the enzyme oxidizes it，releasing electrons and proton”中的it指代glucose，而不是a sugary liquid，因 此C是正确选择。

4. B 第六段的大意是，尽管这种新型燃料电池还不能产牛很多电能，但是，它能够产生电能的事实就已经是很大的成就了。因而激动人心。所以只有B是正确答案。

5. D 文章的最后一段指出了这种新型燃料电池的优点，即A、B、C所述内容。最后一句说，科学家预计，在不到三年的时间里这种新技术便可在大众的流行产品中使用。所以D是正确选择。

译文：

一种新型燃料细胞通过利用活体细胞中很常见的酶能从糖中生产少量的电。如果这项技术能够成功应用于大批量生产，人们可以与自己的手机分享甜饮料(因为糖可以发电供给手机)。

燃料细胞中的化学反应能产生电流。这个过程通常依赖于贵金属，比如铂。在活体细胞中，酶发挥类似的作用，通过分解糖得到电子进而产生能量。

圣路易斯大学的Shelley D.Minteer说，以前研究人员在燃料细胞中使用酶时，很难维持酶的活性。生物细胞能不停地产生新鲜的酶，但燃料细胞中没有能替换很快降解的酶的机制。

Minteer与同样来自圣路易斯大学的TamaraKlotzbach现在研制了一种聚合物，它能包裹酶并将其保存在用显微镜才能看见的袋子里。Minteer解释说：“我们改造袋子使其能为酶提供理想的微环境。”这种聚合物能使酶保持几个月而不是几天的活性。

在新型燃料细胞中，装有酶的微小的聚合物袋子镶嵌在一张裹在一个电极上的薄膜里。含糖液体中的葡萄糖进入袋子时，酶将其氧化，释放出电子和质子。电子穿过薄膜进入一根导线并通过这根导线到达其他电子。导线中的电子与大气中的氧发生反应产生水。电子在导线中流动形成电流，电流能产生电能。

伊利诺斯大学Urbana-Champaign校区的化学工程师Paul Kenis指出，目前这种新型燃料细胞产生不了多少电能，但它们确实产生了电，这一事实令人激动。Kenis说：“单是使它可以产生电能，就是一项大的成果。”

消耗糖的燃料细胞有可能成为高效的发电工具。糖容易得到，而且消耗糖的新型燃料细胞可生物降解，因此这项技术不会损害环境。 目前，科学家们正试图利用别的能从糖中产生更多电的酶。

他们预计，在不到三年的时间里这种新技术便可在大众化的产品中使用。

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