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
10
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、To show that enzymes are very effective.
B、To point out that enzymes can sometimes fail to work.
C、To explain what enzymes are made of.
D、To describe different types of enzymes.
答案
A
解析
细节题。根据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.可知,教授提及锁和钥匙主要是为了表明酶很有效。因此,正确答案为A。
转载请注明原文地址:https://tihaiku.com/zcyy/3537354.html
相关试题推荐
[originaltext]TheEducationSelectCommitteehasbeenexaminingtheunderach
[originaltext]TheeconomiccrisisinEuropeandNorthAmericaledtomoreth
[originaltext]TheeconomiccrisisinEuropeandNorthAmericaledtomoreth
[originaltext]W:Hi,Gary!Isthisseattaken?M:No,itisn’t.Pleasegoright
[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]Let’sbegintodaybydiscussingenzymes.Enzymesarewhatmake
[originaltext]Let’sbegintodaybydiscussingenzymes.Enzymesarewhatmake
随机试题
EatingDisorders:FactsAboutEatingDisordersandtheSearchforSoluti
[audioFiles]audio_eusm_j01_337(20099)[/audioFiles]A、Theoldhousesshouldbetu
对于有卸载机构的大、中型活塞式制冷压缩机来说,采用()方法调节冷量。A.滑阀
1、资料(一) 鑫龙制药(集团)有限公司(以下简称鑫龙制药或公司)是一家较早成
凡两经或三经的病证同时出现者为A.卒发 B.伏发 C.合病 D.并病 E
患者,男性,18岁。确诊金黄色葡萄球菌引起的急性骨髓炎。最佳选药应是A.庆大霉素
使用冰袋降温时,以下护理措施不妥的是A.随时观察冰袋有无漏水 B.冰块融化后应
贾律师在一起未成年人盗窃案件辩护意见中写到:“首先,被告人刘某只是为了满足其上网
某工程施工合同约定根据价格调整公式调整合同价,已知不调值部分占合同价的比例为15
竣工图是水利工程档案的重要组成部分,其中的项目总平面图应由()进行编制。A.施
最新回复
(
0
)