首页
登录
职称英语
For the past forty years it has been known that the ammonia produced
For the past forty years it has been known that the ammonia produced
游客
2025-02-22
8
管理
问题
For the past forty years it has been known that the ammonia produced by
the rhizobia bacteria in soybean roots diffuses through membranes surrounding
bacterial cells into the soybean tissue. Interestingly, these membranes are
Line highly impermeable to organic molecules such as amino acids. Once in the plant
(5) tissue, ammonia can be incorporated into the amino acids glutamine and
glutamate, which are used to synthesize other amino acids and nitrogen-
containing molecules the plant needs, such as proteins, nucleotides and nucleic
acids.
But it has recently been discovered that the ammonium or ammonia formed
(10) by nitrogen fixation is rapidly converted into the amino acid alanine, which is
then transported out of the bacterium; thus little if any fixed nitrogen leaves the
bacteria as ammonia. While researchers remain perplexed by the means through
which alanine actually passes the membranes, they speculate that the process
may keep the newly fixed nitrogen separate from the everyday nitrogen
(15) metabolism of the bacteria themselves, thus ensuring the rapid export of most
of it to the plant. [br] The passage mentions that at various points, scientists have believed all of the following to be essential for the nitrogen fixation process EXCEPT
选项
A、The presence of ammonia
B、The permeability of cell membranes
C、The presence of rhizobia
D、The synthesis of amino acids
E、Nitrogen-containing molecules like nucleotides
答案
E
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3967433.html
相关试题推荐
Forthepastfortyyearsithasbeenknownthattheammoniaproduced
Forthepastfortyyearsithasbeenknownthattheammoniaproduced
Forthepastfortyyearsithasbeenknownthattheammoniaproduced
ThepolarlightsknownasaurorasareproducedwhenchargedsubatomicLine
ThepolarlightsknownasaurorasareproducedwhenchargedsubatomicLine
Bydefinition,teaisproducedfromtheleavesoftheCamelliasinensis,anever
Bydefinition,teaisproducedfromtheleavesoftheCamelliasinensis,anever
Thesoundproducedbytheyouthorchestrawasso______thatevenitsleastexperi
Thoughthevolumeofradioactivewasteproducedbynuclearpowerplantsis______
Nearlytwo-thirdsofthecountry’smushroomcropisproducedby160growersina
随机试题
Doyouhaveanafternoon______thisweektomeetthePresident?A、obtainableB、ava
Whales,severalspeciesofwhichfaceextinction,havebecomesubjectsofconsid
AsSesameStreetkicksoffits40thanniversaryseasonTuesday,withfirstl
Inmanycountries,authorityisseldomquestioned,eitherbecauseitishigh
《中华人民共和国保险法》第三十条规定:“对合同格式条款有两种以上解释的,人民法院
我国生态建设规划有( )。A:加强以京津地区风沙源和水源为重点的治理和保护,建
患者男,50岁。右下肢跛行5年,诊断为雷诺综合征。该患者首选的治疗药物是( )
“生存一关系一成长”理论与马斯洛的需要层次理论的区别有()。A.前者不强调需要
“此日漫挥天下泪,有公足壮海军威”歌颂的是在甲午海战中牺牲的()。A.邓世昌
在经常性安全教育中,最重要的是()。A.安全思想教育 B.安全技术教育
最新回复
(
0
)