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TED-Ed演讲:如何把熟蛋变生(2)

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  发表于 Apr 23, 2018 16:27:24 | 只看该作者 回帖奖励 |倒序浏览 |阅读模式
TED-Ed演讲:如何把熟蛋变生(2)
Here's the key part.
接下来是关键的部分。
The solution nearest the wall spins faster than the solution closer to the middle.
离试管壁最近的溶液,要比中间的溶液旋转得更快。
That difference in velocity creates sheer stresses that repeatedly stretch and contract the proteins
这个速度上的区别产生了剪切应力,会重复拉伸和收缩蛋白质,
until eventually they snap back into their native shapes and stay there.
直到最后它们恢复成原始的形状,并稳定下来。
By the time the centrifuge stops spinning, the egg white is back in its original unboiled state.
当离心机停止旋转,鸡蛋白就恢复成了未被煮过的形态。
This technique works with all sorts of proteins.
这项技术适用于所有蛋白质。
Bigger, messier proteins can be more resistant to being pulled apart,
更大和更混乱的蛋白质将会更难还原,
so scientists attach a plastic bead to one end that adds extra stress and encourages it to fold up first.
所以科学家会在蛋白质的一端黏上一个塑料珠,以此来产生额外的重量,并会加大收缩,促使其先折叠。
This unboiling method won't work with a whole egg in its shell
这个方法不适用于一个完整的带壳的蛋,
since the solution has to spread throughout a cylindrical chamber.
因为溶液必须在圆柱体容器内展开。
But the applications go way beyond uncooking your breakfast, anyhow.
但这一实际应用远超出还原你的早餐。
Many pharmaceuticals consist of proteins that are extremely expensive to produce,
很多含有蛋白质的药物的生产费用非常高,
partly because they get stuck in tangled up aggregates,
有些是因为他们卡在了聚集蛋白质中,
just like cooked egg whites and have to be untangled and refolded before they can do their jobs.
就像煮熟的蛋白,这些必须在他们开始工作前被打散和展开。
This spinning technique has the potential to be an easier, cheaper and quicker method than other ways to refold proteins,
这个旋转方法,相比于其他再折叠蛋白质的方式,能成为更简单、便宜、快速的方法。
so it may allow new drugs to be made available to more people faster.
所以,它可能会使新药物的出现变得更加快捷。
And there's one more thing you need to keep in mind before trying to uncook all of your food.
在还原你的食物之前,还有一件事情需要你记住。
Boiling an egg is actually an unusual cooking process
煮蛋实际上是个不寻常的过程,
because even though it changes the way proteins are shaped and bound together,
因为即使它使蛋白质的形状和连接方式发生了改变,
it doesn't actually change their chemical identity.
但它的化学性质并没有改变。
Most types of cooking are more like the famous Maillard reaction, which makes chemical changes
大多数烹饪过程类似着名的“梅拉德反应”,就是会发生化学变化,
that turn sugars and proteins into delicious caramel crunchiness and are a lot harder to undo.
将糖分和蛋白质转换成美味的焦糖脆,这会非常难还原。
So you might be able to unboil your egg, but I'm sorry to say you can't unfry it...yet.
所以,你可以还原你的煮蛋,但很抱歉,到目前为止,你还不能还原你的煎蛋。

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