TED演讲：细菌是怎样交流的(3)_在线英语听力室

(单词翻译:双击或拖选)

　　What was actually interesting to us was not that the bacteria made light, but when the bacteria made light. 事实上，我们感兴趣的部分并不是细菌会不会发光，而是细菌何时发光。

　　What we noticed is when the bacteria were alone, so when they were in dilute¹ suspension, they made no light. 我们发现，当细菌独立存在，经稀释后进行悬浮培养时，它们不发光。

　　But when they grew to a certain cell number all the bacteria turned on light simultaneously². 但一旦它们增长到一个特定数量之后，所有的细菌同时发光。

　　The question that we had is how can bacteria, these primitive³ organisms, tell the difference from times when they're alone, 于是我们想，这些原始生物，到底如何得知自己是处于孤立的状态

　　and times when they're in a community, and then all do something together. 还是处在一个群体里，并且同时一起做同一件事情。

　　What we've figured out is that the way that they do that is that they talk to each other, and they talk with a chemical language. 然后我们发现了这是因为细菌能够彼此交谈，它们用的是化学语言。

　　This is now supposed to be my bacterial⁴ cell. When it's alone it doesn't make any light. 假设这是我的细菌。当它独处时，根本不会发光。

　　But what it does do is to make and secrete⁵ small molecules⁷ that you can think of like hormones⁸, 但是它们会制造、分泌小的分子，你可以把他想象成荷尔蒙，

　　and these are the red triangles, and when the bacteria is alone the molecules just float away and so no light. 这里的红色三角形代表这些小分子，当细菌独处时，分泌的小分子游离开来，所以不发光。

　　But when the bacteria grow and double and they're all participating in making these molecules, 但是随着这些细菌成倍增长，并且全部一起制造这些分子，

　　the molecule⁶ -- the extracellular amount of that molecule increases in proportion to cell number. 这些细胞外分子的含量随着细胞数量的增加而增加。

　　And when the molecule hits a certain amount that tells the bacteria how many neighbors there are, 当这些个分子累积到一定的量之后，它们会告诉细菌它们周围有多少邻居，

　　they recognize that molecule and all of the bacteria turn on light in synchrony. 细菌接受到这些信息后，所有的细菌同时开始发光。

　　And so that's how bioluminescence works -- they're talking with these chemical words. 生物发光就是这样运作的--它们通过上述的化学语言进行交流。

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收听单词发音

1 dilute
vt.稀释，冲淡；adj.稀释的，冲淡的
参考例句：
The water will dilute the wine.水能使酒变淡。 Zinc displaces the hydrogen of dilute acids.锌置换了稀酸中的氢。

2 simultaneously
adv.同时发生地，同时进行地
参考例句：
The radar beam can track a number of targets almost simultaneously.雷达波几乎可以同时追着多个目标。 The Windows allow a computer user to execute multiple programs simultaneously.Windows允许计算机用户同时运行多个程序。

3 primitive
adj.原始的；简单的；n.原(始)人，原始事物
参考例句：
It is a primitive instinct to flee a place of danger.逃离危险的地方是一种原始本能。 His book describes the march of the civilization of a primitive society.他的著作描述了一个原始社会的开化过程。

4 bacterial
a.细菌的
参考例句：
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。

5 secrete
vt.分泌；隐匿，使隐秘
参考例句：
The pores of your body secrete sweat.身上的毛孔分泌汗液。 Squirrels secrete a supply of nuts for winter.松鼠为准备过冬而藏坚果。

6 molecule
n.分子，克分子
参考例句：
A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈̬f婘̬ 妈̬成的。 This gives us the structural formula of the molecule.这种方式给出了分子的结构式。

7 molecules
分子( molecule的名词复数 )
参考例句：
The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。 Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

8 hormones
n. 荷尔蒙，激素名词hormone的复数形式
参考例句：
This hormone interacts closely with other hormones in the body. 这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。 The adrenals produce a large per cent of a man's sex hormones. 肾上腺分泌人体的大部分性激素。

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TED演讲：细菌是怎样交流的(3)