首页
登录
职称英语
[originaltext] Let’s begin today by discussing enzymes. Enzymes are what make
[originaltext] Let’s begin today by discussing enzymes. Enzymes are what make
游客
2024-04-02
31
管理
问题
Let’s begin today by discussing enzymes. Enzymes are what make many of the body’ s biochemical reactions pos sible. Actually biochemical reactions can take place without them, but at much lower rates. In fact an enzyme may cause a reaction to proceed billions of times faster than it would otherwise. Before I go on to the biochemical specifics of how this works, let me provide a figurative example. I think it will help illustrate the power of enzymes more clearly. Now, suppose you got a bag and you put a bunch of locks in it. Then you put in all the keys that go with the locks. And you closed the bag and shook it hard. No matter how long you shook, chances are very small that any key would get inserted in any of the locks. But if you took them all out of the bag and this time used your hands to insert the keys in the locks, you could combine them much quicker.Enzymes act like your hands, quickly allowing chemical reactions that would otherwise take much longer. Now, there are two reasons that enzymes are so effective at enabling biochemical reactions. First enzymes greatly reduce the amount of energy required to start the reactions, and with less energy needed the reactions can proceed a lot faster than they could without the enzyme. The second reason is that on a small amount of an enzyme is needed to enable the biochemical reaction. That’s because the chemical structure of the enzyme itself does not become altered as if enables the reaction. So a single enzyme can be used to start the same biochemical reaction over and over again.
Now listen to the following recording and answer questions 19 to 21.
19. What point does the professor make about an enzyme when it is involved in a biochemical reaction?
20. What do enzymes do to help start a biochemical reaction?
21. Why does the professor talk about locks and keys?
选项
A、It divides into two different parts.
B、It keeps the same chemical structure.
C、It becomes part of a new chemical compound.
D、It produces more of the enzyme(酶).
答案
B
解析
细节题。根据讲座内容及结尾的That’s because the chemical structure of the enzyme itself does not become altered as if enables the reaction.So a single enzyme can be used to start the same biochemical reaction over and over again.可知,教授指出酶在生化反应中保持不变的化学结构。因此,正确答案为B。
转载请注明原文地址:https://tihaiku.com/zcyy/3537352.html
相关试题推荐
[originaltext]TheEducationSelectCommitteehasbeenexaminingtheunderach
[originaltext]TheeconomiccrisisinEuropeandNorthAmericaledtomoreth
[originaltext]W:Hi,Gary!Isthisseattaken?M:No,itisn’t.Pleasegoright
[originaltext]W:Hi,Gary!Isthisseattaken?M:No,itisn’t.Pleasegoright
[originaltext]TodayI’dliketotalkaboutthesculptorHenryMoore,inpar
[originaltext]TodayI’dliketotalkaboutthesculptorHenryMoore,inpar
[originaltext]TodayI’dliketotalkaboutthesculptorHenryMoore,inpar
[originaltext]TodayI’dliketotalkaboutthesculptorHenryMoore,inpar
[originaltext]Let’sbegintodaybydiscussingenzymes.Enzymesarewhatmake
[originaltext]Let’sbegintodaybydiscussingenzymes.Enzymesarewhatmake
随机试题
Thefoodandwaterthatpeople(consumethem)comefromtheenvironment,(provid
Thewomangoestothemanwiththeaimto[originaltext]W:Goodmorning,Prof.G
[audioFiles]audio_eufm_j04_001(20082)[/audioFiles]A、Shewilldothejobsforhi
[originaltext]M:Goodmorning,Amanda!W:Hi,Mike!Niceday,isn’tit?M:Yeah
因无形资产侵权损害而导致纠纷的评估目的是()。A.法律诉讼 B.出资 C.
在中央银行的一般性货币政策工具中,与存款准备金政策相比,公开市场业务的优点之一是
《商业银行与内部人和股东关联交易管理办法》规定,商业银行对全部关联方的授信余额不
对传染病和疑似传染病患者,应当采取A.就地控制、就地治疗、就地康复 B.就地隔
2020年全国农民工总量28560万人,比上年减少517万人。其中,外出农民工1
某宗房地产的正常成交价格为2500元/m2,卖方应缴纳的税费为正常成交价格的7%
最新回复
(
0
)