首页
登录
职称英语
[originaltext] Let’ s begin today by discussing enzymes. Enzymes are what ma
[originaltext] Let’ s begin today by discussing enzymes. Enzymes are what ma
游客
2024-04-09
71
管理
问题
Let’ s begin today by discussing enzymes. Enzymes are what make many of the body’ s biochemical reactions possible. 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 mat 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:http://tihaiku.com/zcyy/3547513.html
相关试题推荐
[originaltext]TodayI’dliketotalkaboutthesculptorHenryMoore,inpa
[originaltext]TodayI’dliketotalkaboutthesculptorHenryMoore,inpa
[originaltext]Let’sbegintodaybydiscussingenzymes.Enzymesarewhatma
[originaltext]Inthe18thcenturyFrencheconomistsprotestedtheexcessive
[originaltext]Inthe18thcenturyFrencheconomistsprotestedtheexcessive
[originaltext]TheEducationSelectCommitteehasbeenexaminingtheunderac
[originaltext]TheEducationSelectCommitteehasbeenexaminingtheunderac
[originaltext]TheEducationSelectCommitteehasbeenexaminingtheunderac
[originaltext]TheEducationSelectCommitteehasbeenexaminingtheunderac
[originaltext]TheeconomiccrisisinEuropeandNorthAmericaledtomoret
随机试题
Obviously,Africanartisneitheranti-classicalnoranti-naturalistic:tobeei
TrainingprogramsfortheU.S.PeaceCorpsareconductedinthecountryorregi
[img]2016m3x/ct_eyyjsbz2015c_eyyjsbreada_0058_20163[/img]Eagles,soaringhi
KarenCollinsHenry,wholostherrealestatejobwhenthehousingmarketbe
某男,43岁。少腹引控睾丸而痛,偏坠肿胀,少腹疼痛,苔白,脉弦。治宜选用A.少腹
胆的主要生理功能是A.贮藏胆汁以助消化 B.传化水谷 C.主决断 D.泌别
孕妇,32岁,经产妇,妊娠36周,LOA,少量阴道流血2日,胎心140次/分,怀
2011年上半年,内地对台湾地区农产品净出口额(出口额一进口额)为()亿美元
记账式国债的特点不包括()。 A.具有一定的风险 B.期限有长有短,
某分项工程招标工程量清单数量为1000m3,施工中由于设计变更调整为1200m3
最新回复
(
0
)