ADM-201 dump PMP dumps pdf SSCP exam materials CBAP exam sample questions

如何将熟蛋变回生蛋 – 译学馆
未登陆,请登陆后再发表信息
最新评论 (0)
播放视频

如何将熟蛋变回生蛋

How to unboil an egg - Eleanor Nelsen

很明显(简直)称得上是众所周知了
It’s so obviousthat it’s practically proverbial.
你不可能把一个熟蛋变生
You can’t unboil an egg. Well,
其实是可以的 某种意义上说
it turns out you can, sort of.
热能对蛋的分子所做的事
What thermal energydoes to the eggs’ molecules,
可以依靠机械能将其还原
mechanical energy can undo.
蛋主要由水和蛋白质组成
Eggs are mostly madeof water and proteins.
蛋白质开始是一种交织着的复杂的形状
The proteins start offfolded up into intricate shapes,
依靠弱的化学键连接在一起
held together by weak chemical bonds.
加热能破坏这些化学键
Adding heat disrupts those bonds,
使蛋白质能够展开 解开 分离 变得可以自由摆动
allowing the proteins to unfold,uncoil, unwind and wiggle freely.
这个过程被称为“变性”
This process is called denaturing.
新“解放”的蛋白质 会与邻近的彼此撞击
The newly liberated proteinsbump up against their neighbors
并相互形成新的化学键
and start to formnew bonds with each other,
当热量变得越来越多后
more and more as the heat increases,
最后它们将形成
until finally, they’re so entangled
一团固体
that they gel into a solid mass,
一个煮熟的蛋
a boiled egg.
那种缠绕可能看起来不可逆 但其实不然
That entanglement might lookpermanent, but it’s not.
根据一种叫做微观可逆原理的化学观点
According to a chemical idea called the principle of microscopic reversibility,
任何已发生的事情 比如说鸡蛋中的蛋白质变为固体的情况
anything that happens,like egg proteins seizing up,
如果每步都反过来进行 理论上应该可以将其还原
can theoretically unhappenif you retrace your steps.
但增加更多的热量 只会使蛋白质纠缠的更紧
But adding more heat will tanglethe proteins further,
而冷却只会冻住它们
and cooling them downwill only freeze them,
所以这里的秘诀是:将其极快的旋转
so here’s the trick: spin them around ridiculously fast.
我没在开玩笑
I’m not kidding.
以下就是其原理 首先
Here’s how it works. First,
科学家在水中加入一种名为尿素的化学物质
scientists dissolveboiled egg whites in water
即一种小分子 起到润滑剂的作用
with a chemical called urea,
将煮熟的蛋白溶解
a small molecule that acts as a lubricant,
附着在蛋白质较长的一股
coating the proteins’ long strands
使它们更容易得滑过对方 然后
and making it easier for themto glide past each other. Then,
他们将溶液放入试管
they spin that solutionin a glass tube
以极快的 5000转每分钟的速度旋转
at a breakneck 5000 rotations per minute,
使得溶液展开 形成一层很薄的生物膜
making the solutionspread out into a thin film.
接下来是关键的部分
Here’s the key part.
离试管壁最近的溶液
The solution nearestthe wall spins faster
要比中间的溶液旋转得更快
than the solution closer to the middle.
这个速度上的区别产生了剪切应力
That difference in velocitycreates sheer stresses
会重复拉伸和收缩蛋白质
that repeatedly stretchand contract the proteins
直到最后它们恢复成最初的形状 并稳定下来
until eventually they snap back into their native shapes and stay there.
当离心机停止旋转
By the time the centrifuge stops spinning,
鸡蛋白就恢复成了未被煮过的形态
the egg white is backin its original unboiled state.
这项技术适用于所有蛋白质
This technique workswith all sorts of proteins. Bigger,
更大和更混乱的蛋白质将会更难还原
messier proteins can bemore resistant to being pulled apart,
所以科学家会在蛋白质的一端黏上一个塑料珠
so scientists attacha plastic bead to one end
以此来产生额外的重量 并会加大收缩 促使其先折叠
that adds extra stressand encourages it to fold up first.
这个方法不适用完整的带壳的蛋
This unboiling method won’t work
带壳的整个鸡蛋
with a whole egg in its shell
因为溶液必须在圆柱体容器内展开
since the solution has to spreadthroughout a cylindrical chamber.
但这一实际应用远超过还原你的早餐
But the applications go way beyonduncooking your breakfast, anyhow.
很多含有蛋白质的药物的生产费用非常高
Many pharmaceuticals consist of proteinsthat are extremely expensive to produce,
有些是因为他们卡在了聚集蛋白质中
partly because they get stuckin tangled up aggregates,
就像煮熟的蛋白
just like cooked egg whites
这些必须在他们开始工作前被打散并展开
and have to be untangled and refolded before they can do their jobs.
这项旋转技术
This spinning technique has the potential
相比于其他再折叠蛋白质的方式
to be an easier, cheaperand quicker method
能成为更简单 便宜 快速的方法
than other ways to refold proteins,
所以 它可能会使新药物的出现变得更加快捷
so it may allow new drugs to be made available to more people faster.
在还原你的食物之前
And there’s one more thingyou need to keep in mind
还有一件事情需要记住
before trying to uncook all of your food.
煮蛋实际上是个不寻常的过程
Boiling an egg is actuallyan unusual cooking process
因为即使它使
because even though it changes the
蛋白质的形状和连接方式发生了改变
way proteins are shaped and bound together,
但它的化学性质并没有改变
it doesn’t actually changetheir chemical identity.
大多数烹饪过程类似著名的“梅拉德反应”
Most types of cooking are more likethe famous Maillard reaction,
就是会发生化学变化
which makes chemical changes that turn
将糖分和蛋白质转换成美味的焦糖脆
sugars and proteins into delicious caramel crunchiness
这会非常难还原
and are a lot harder to undo.
所以 你可以还原你的煮蛋
So you might be able to unboil your egg,
但很抱歉 到目前为止 你还不能还原你的煎蛋
but I’m sorry to sayyou can’t unfry it…yet.

发表评论

译制信息
视频概述

大胆的化学理论方式,脑洞大开。

听录译者

收集自网络

翻译译者

甪里

审核员

审核员 V

视频来源

https://www.youtube.com/watch?v=CHMY4G9gTPA

相关推荐