SSS 2010-12-02
时间：2019-01-08 作者：英语课 分类：Scientific American(十二)月
This is Scientific American's 60-Second Science, I'm Christopher Intagliata. Got a minute?
Life on earth requires six basic ingredients—carbon, hydrogen, nitrogen, oxygen, sulfur 1 and phosphorus. Those six elements are the building blocks for DNA 2 and RNA, along with proteins and fats. Which means they're essential for life—as we know it. But it might be time to update that list. Because scientists have found a bacterium 3 that can do without phosphorus—live on arsenic 4 instead.
Researchers had a hunch 5 a bug 6 like this might exist because arsenic has some chemical properties in common with phosphorus. So they collected mud from California's Mono Lake, where the waters are naturally salty, and laced with arsenic. Back in the lab, they cultured microbes from that mud. But instead of adding phosphorus to the cultures to help the bugs 7 grow, they added varying levels of arsenic.
One bacterial 8 strain continued to thrive. And tests confirmed that the organisms compensated 9 for the lack of phosphorus by building their DNA with arsenic instead. The research appears in the journal Science. This is the first known life form that seems to be able to swap 10 out one of life's fundamental building blocks with another element. So for astrobiologists hunting for life in space, don't rule out places filled with poison.
Thanks for the minute. For Scientific American's 60-Second Science, I'm Christopher Intagliata.
- Sulfur emissions from steel mills become acid rain.炼钢厂排放出的硫形成了酸雨。
- Burning may produce sulfur oxides.燃烧可能会产生硫氧化物。
- DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
- Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。
- The bacterium possibly goes in the human body by the mouth.细菌可能通过口进入人体。
- A bacterium is identified as the cause for his duodenal ulcer.一种细菌被断定为造成他十二指肠溃疡的根源。
- I have a hunch that he didn't really want to go.我有这么一种感觉，他并不真正想去。
- I had a hunch that Susan and I would work well together.我有预感和苏珊共事会很融洽。
- There is a bug in the system.系统出了故障。
- The bird caught a bug on the fly.那鸟在飞行中捉住了一只昆虫。
- All programs have bugs and need endless refinement. 所有的程序都有漏洞，都需要不断改进。 来自《简明英汉词典》
- The sacks of rice were swarming with bugs. 一袋袋的米里长满了虫子。 来自《简明英汉词典》
- Bacterial reproduction is accelerated in weightless space. 在失重的空间，细菌繁殖加快了。
- Brain lesions can be caused by bacterial infections. 大脑损伤可能由细菌感染引起。
- The marvelous acting compensated for the play's weak script. 本剧的精彩表演弥补了剧本的不足。
- I compensated his loss with money. 我赔偿他经济损失。