TED演讲之身体语言 气味背后的科学(4)
Here's how shape works in normal receptors.
这里展示的是形状是如何对通常的感受器起作用的。
You have a molecule coming in, it gets into the protein, which is schematic here,
一个分子进来，进到蛋白质里，图中所示意的就是蛋白质，
and it causes this thing to switch, to turn, to move in some way by binding in certain parts.
通过合并某些部分，它让这个东西转变、旋转向某个方向移动起来。
And the attraction, the forces, between the molecule and the protein cause the motion. This is a shape-based idea.
分子和蛋白质之间的互相吸引和作用力造成了运动。这是基于形状理论的想法。
Now, what's wrong with shape is summarized in this slide.
这张幻灯片总结了为什么形状理论是错误的。
The way –I expect everybody to memorize these compounds.
这种方式–我希望每一个人把这些化合物都记住。
This is one page of work from a chemist's workbook, OK?
这是一个化学家工作手册中的一页。
Working for a fragrance company.
他为一家香水公司工作。
He's making 45 molecules, and he's looking for a sandalwood, something that smells of sandalwood.
他要制造45个分子，他正在寻找檀香料就是闻起来像檀香木的东西。
Because there's a lot of money in sandalwoods.
因为檀香木很贵。
And of these 45 molecules, only 4629 actually smells of sandalwood.
在这45个分子之中只有编号为4629的闻起来像檀香木。
And he puts an exclamation mark, OK?
于是他在上面标注了一个感叹号。
This is an awful lot of work.
这个工作量很大。
This actually is roughly, in man-years of work, 200,000 dollars roughly, if you keep them on the low salaries with no benefits.
在低酬劳和没有福利的条件下，这大概是一个人好几年的工作量，大约需要20万美金。
So this is a profoundly inefficient process.
这是一个效率极低的过程。
And my definition of a theory is, it's not just something that you teach people; it's labor saving.
我认为“理论”不仅是可以拿来教授别人的东西，同时也是节约劳动力的东西。
A theory is something that enables you to do less work.
一个理论可以使人们做更少的工作。
I love the idea of doing less work.
我喜欢少做工作这个想法。
So let me explain to you why — a very simple fact that tells you why this shape theory really does not work very well.
让我来解释为什么，一个非常简单的事实，它会告诉你们为什么形状的理论并不成立。
This is cis-3-hexene-1-ol. It smells of cut grass.
这是顺式-3-已烯-1-醇。闻起来像割下来的青草。
This is cis-3-hexene-1-thiol, and this smells of rotten eggs, OK?
这是顺式-3-已烯-1-硫醇，闻起来像臭鸡蛋。
Now, you will have noticed that vodka never smells of rotten eggs.
现在，你们一定已经意识到伏特加酒闻起来绝不像臭鸡蛋。
If it does, you put the glass down, you go to a different bar.
如果闻起来像的话，你就把杯子放下去另外一家酒吧。
This is — in other words, we never get the O-H — we never mistake it for an S-H, OK?
这是–换句话说，我们绝对不会把S-H错误地认为是O-H。
Like, at no concentration, even pure, you know, if you smelt pure ethanol, it doesn't smell of rotten eggs.
无论是在什么样的浓度甚至是纯的情况下，如果你闻到纯的乙醇，它闻起来绝对不像臭鸡蛋。
Conversely, there is no concentration at which the sulfur compound will smell like vodka.
相反，无论在什么浓度下，硫化合物会闻起来都不会像伏特加酒。
It's very hard to explain this by molecular recognition.
用分子识别来解释这个问题难度很大。
Now, I showed this to a physicist friend of mine who has a profound distaste for biology,
我把问题拿给我的一个物理学家朋友看，他一点也不喜欢生物，
and he says, "That's easy! The things are a different color!"
他说“这太简单了！两个东西的颜色不一样啊！”
演讲简介：
令人神魂颠倒的香水蕴含着什么样的科学？生物物理学家Luca Turin用精准和充满魅力的语言，为大家解释气味的分子组成及其背后的艺术。
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